Silicate-containing alkaline compositions for cleaning microelectronic substrates

ABSTRACT

The invention provides aqueous alkaline compositions useful in the microelectronics industry for stripping or cleaning semiconductor wafer substrates by removing photoresist residues and other unwanted contaminants. The compositions typically contain (a) one or more metal ion-free bases at sufficient amounts to produce a pH of about 10-13 and one or more bath stabilizing agents having at least one pKa in the range of 10-13 to maintain this pH during use; (b) optionally, about 0.01% to about 5% by weight (expressed as % SiO.sub.2) of a water-soluble metal ion-free silicate; (c) optionally, about 0.01% to about 10% by weight of one or more chelating agents; (d) optionally, about 0.01% to about 80% by weight of one or more water-soluble organic co-solvents; and (e) optionally, about 0.01% to about 1% by weight of a water-soluble surfactant.

This application claims the benefit of provisional application No.60/085,861 filed May 18, 1998 and No. 60/115,084, filed Jan. 7, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to compositions useful in the microelectronicsindustry for cleaning semiconductor wafer substrates. Particularly, thisinvention relates to alkaline stripping or cleaning compositionscontaining metal ion-free silicates that are used for cleaning wafershaving metal lines and vias by removing metallic and organiccontamination without damaging the integrated circuits.

2. Description of the Prior Art

An integral part of microelectronic fabrication is the use ofphotoresists to transfer an image from a mask or reticle to the desiredcircuit layer. After the desired image transfer has been achieved, anetching process is used to form the desired structures. The most commonstructures formed in this way are metal lines and vias.

The metal lines are used to form electrical connections between variousparts of the integrated circuit that lie in the same fabrication layer.The vias are holes that are etched through dielectric layers and laterfilled with a conductive metal. These are used to make electricalconnections between different vertical layers of the integrated circuit.A halogen containing gas is generally used in the processes used forforming metal lines and vias.

After the etching process has been completed, the bulk of thephotoresist may be removed by either a chemical stripper solution or byan oxygen plasma ashing process. The problem is that these etchingprocesses produce highly insoluble metal-containing residues that maynot be removed by common chemical stripper solutions. Also, during anashing process the metal-containing residues are oxidized and made evenmore difficult to remove, particularly in the case of aluminum-basedintegrated circuits. See, “Managing Etch and Implant Residue,”Semiconductor International, August 1997, pages 56-63.

An example of such an etching process is the patterning of metal lineson an integrated circuit. In this process, a photoresist coating isapplied over a metal film then imaged through a mask or reticle toselectively expose a pattern in the photoresist coating. The coating isdeveloped to remove either exposed or unexposed photoresist, dependingon the tone of the photoresist used, and produce a photoresist on themetal pattern. The remaining photoresist is usually hard-baked at hightemperature to remove solvents and optionally to cross-link the polymermatrix. The actual metal etching step is then performed. This etchingstep removes metal not covered by photoresist through the action of agaseous plasma. Removal of such metal transfers the pattern from thephotoresist layer to the metal layer. The remaining photoresist is thenremoved (“stripped”) with an organic stripper solution or with an oxygenplasma ashing procedure. The ashing procedure is often followed by arinsing step that uses a liquid organic stripper solution. However, thestripper solutions currently available, usually alkaline strippersolutions, leave insoluble metal oxides and other metal-containingresidues on the integrated circuit.

Another example of such an etching process is the patterning of vias(interconnect holes) on an integrated circuit. In this process, aphotoresist coating is applied over a dielectric film then imagedthrough a mask or reticle to selectively expose a pattern in thephotoresist coating. The coating is developed to remove either exposedor unexposed photoresist, depending on the tone of the photoresist used,and produce a photoresist on the metal pattern. The remainingphotoresist is usually hard-baked at high temperature to remove solventsand optionally to cross-link the polymer matrix. The actual dielectricetching step is then performed. This etching step removes dielectric notcovered by photoresist through the action of a gaseous plasma. Removalof such dielectric transfers the pattern from the photoresist layer tothe dielectric layer. The remaining photoresist is then removed(“stripped”) with an organic stripper solution or with an oxygen plasmaashing procedure. Typically, the dielectric is etched to a point wherethe underlying metal layer is exposed. A titanium or titanium nitrideanti-reflective or diffusion barrier layer is typically present at themetal/dielectric boundary. This boundary layer is usually etched throughto expose the underlying metal. It has been found that the action ofetching through the titanium or titanium nitride layer causes titaniumto be incorporated into the etching residues formed inside of the via.Oxygen plasma ashing oxidizes these via residues making them moredifficult to remove. A titanium residue removal enhancing agent musttherefore be added to the stripper solution to enable the cleaning ofthese residues. See “Removal of Titanium Oxide Grown on Titanium Nitrideand Reduction of Via Contact Resistance Using a Modern Plasma Asher”,Mat. Res. Soc. Symp. Proc., Vol. 495, 1998, pages 345-352. The ashingprocedure is often followed by a rinsing step that uses a liquid organicstripper solution. However, the stripper solutions currently available,usually alkaline stripper solutions, leave insoluble metal oxides andother metal-containing residues on the integrated circuit. There aresome hydroxylamine-based strippers and post-ash residue removers on themarket that have a high organic solvent content, but they are not aseffective on other residues found in vias or on metal-lines. They alsorequire a high temperature (typically 65° C. or higher) in order toclean the residues from the vias and metal-lines.

The use of alkaline strippers on microcircuit containing metal films hasnot always produced quality circuits, particularly when used with metalfilms containing aluminum or various combinations or alloys of activemetals such as aluminum or titanium with more electropositive metalssuch as copper or tungsten. Various types of metal corrosion, such ascorrosion whiskers, pitting, notching of metal lines, have been observeddue, at least in part, to reaction of the metals with alkalinestrippers. Further it has been shown, by Lee et al., Proc. Interface'89, pp. 137-149, that very little corrosive action takes place untilthe water rinsing step that is required to remove the organic stripperfrom the wafer. The corrosion is evidently a result of contacting themetals with the strongly alkaline aqueous solution that is presentduring rinsing. Aluminum metal is known to corrode rapidly under suchconditions, Ambat et al., Corrosion Science, Vol. 33 (5), p. 684. 1992.

Prior methods used to avoid this corrosion problem employed intermediaterinses with non-alkaline organic solvents such as isopropyl alcohol.However, such methods are expensive and have unwanted safety, chemicalhygiene, and environmental consequences.

The prior art discloses several organic strippers used to remove bulkphotoresist after the etching process. U.S. Pat. Nos. 4,765,844,5,102,777 and 5,308,745 disclose photoresist strippers comprisingvarious combinations of organic solvents. These strippers, however, arenot very effective on wafers that have been “ashed” with oxygen plasmasas described above. Some photoresist strippers attempt to address thisproblem by adding additional water and an organic corrosion inhibitorsuch as catechol. Such compositions are disclosed in U.S. Pat. Nos.5,482,566, 5,279,771, 5,381,807, 5,334,332, 5,709,756, 5,707,947, and5,419,779 and in WO 9800244. In some cases, the hydrazine derivative,hydroxylamine, is added as well. Because of its toxicity, the use ofcatechol gives rise to various environmental, safety, and healthconcerns.

Metal silicates have been included as corrosion inhibitors in cleaningsolutions used on electronic circuit boards. Examples of such solutionsare disclosed in SU 761976, DD 143,920, DD 143,921, U.S. Pat. Nos.5,264,046, 5,234,505, 5,234,506, and 5,393,448. The metal lines oncircuit boards are much larger than those found in integrated circuitsthus have less demanding cleaning requirements. In the case ofintegrated circuits, metal contamination introduced from a cleaningsolution, even at extremely low concentrations, can cause prematurefailure of the device. Therefore, any formulation containingintentionally added metals, such as the metal silicates cited above,would be detrimental to integrated circuit device performance andreliability. U.S. Pat. No. 4,659,650 discloses using a sodiummetasilicate solution to dissolve metal lift-off masks.

In U.S. Pat. No. 5,817,610 and EP 829,768 the use of a quaternaryammonium silicate, quaternary ammonium hydroxide and water is disclosedfor use in removing plasma etch residues. In these two disclosures,catechol oligimers are preferred over quaternary ammonium silicates ascorrosion inhibitors and no examples of quaternary ammonium silicatesbeing used as corrosion inhibitors are shown. In U.S. Pat. No. 5,759,973and EP 828,197 the use of a quaternary ammonium silicate, an aminecompound, water and optionally an organic polar solvent is disclosed foruse as a stripping and cleaning composition. None of the fourdisclosures cited above discloses the advantages of adding anaminocarboxylic acid buffering agent or titanium residue removalenhancer. None of the four disclosures cited above discloses theadvantages of adding a titanium residue removal enhancer. The presentinvention has shown that in some cases it is necessary to add a titaniumresidue removal enhancer for effective cleaning of some residuescontaining titanium found after a plasma etch process. U.S. Pat. No.5,759,973 and EP 828,197 disclose the use of a chelating agent selectedfrom sugars such as glucose, fructose or sucrose and sugar alcohols suchas xylitol, mannitol and sorbitol. Lab tests of formulations of thepresent invention with fructose or sorbitol added resulted in a solutionthat was not as pH stable as formulations having an aminocarboxylic acidor no added chelating or buffering agent added.

Patent application WO 9523999 discloses using tetramethylammoniumsilicate and ammonium silicate as corrosion inhibitors in solutions usedfor removing resist from circuit boards. However, the lack of any(ethylenedinitrilo) tetraacetic acid (EDTA) content was described as anadvantage of the disclosed formulation. In the present invention, incontrast, the optional use of chelating agents such as EDTA wasbeneficial.

Other uses of silicate inhibitors include magnetic head cleaners (JP09,245,311), laundry detergents (WO 9,100,330), metal processingsolutions (DE 2,234,842. U.S. Pat. Nos. 3,639,185, 3,773,670, 4,351,883,4,341,878, EP 743,357, U.S. Pat. No. 4,710,232), rosin flux removers(U.S. Pat. No. 5,549,761), and photoresists (JP 50,101,103).

Both metal ion-free silicates such as tetramethylammonium silicate andmetal silicates have been used as components of photoresist developers(U.S. Pat. No. 4,628,023, JP 63,147,163, U.S. Pat. Nos. 4,822,722,4,931,380, RD 318,056, RD 347,073, EP 62,733). Photoresist developersare used before the etching and oxygen plasma ashing processes to removepatterned photoresist areas which have been altered by exposure tolight. This leaves a photoresist pattern on the wafer surface which istypically “hardened” by exposure to light and heat to form an etchingmask. This mask is used during the plasma etching step and usuallyremoved after this use by an oxygen plasma “ashing” step. The presentinvention relates to the removal of residues formed during these lasttwo steps and is unrelated to the photoresist development step addressedby the patents cited in this paragraph.

Solutions prepared by dissolving silicic acid or solid silicon intetramethylammonium hydroxide (TMAH) have been reported as useful forthe passivation of aluminum structures during micromachining (“Aluminumpassivation in Saturated TMAHW Solutions for IC-CompatibleMicrostructures and Device Isolation”, Sarrow. et al., SPIE Vol. 2879,Proceedings-Micromachining and Microfabrication Process Technology II,The International Society for Optical Engineering, Oct. 14-15, 1996, pp.242-250). Micromachining applications are outside of the scope of thepresent invention. The solutions in the cited reference contain about 25weight percent silicate (expressed as SiO₂). This concentration issignificantly greater than the concentrations used in the examples ofthis invention, which range from about 0.01 to about 2.9 weight percentsilicate (expressed as SiO₂). The use of the chelating agent catechol asa silicon etch rate enhancer is also suggested. In the presentinvention, increasing the etch rate of silicon would be undesirablesince this might damage the silicon dioxide dielectric layers commonlyused in integrated circuits as well as the exposed silicon backside ofthe wafer.

The use of a quaternary ammonium hydroxide in photoresist strippers isdisclosed in U.S. Pat. Nos. 4,776,892, 5,563,119; JP 09319098 A2; EP578507 A2: WO 9117484 A1 and U.S. Pat. No. 4,744,834. The use ofchelating and complexing agents to sequester metals in various cleanershas also been reported in WO 9705228, U.S. Pat. Nos. 5,466,389,5,498,293, EP 812011, U.S. Pat. No. 5,561,105, JP 06216098, JP 0641773,JP 06250400 and GB 1,573,206.

U.S. Pat. No. 5,466,389 discloses an aqueous alkaline containingcleaning solution for microelectronics substrates that contains aquaternary ammonium hydroxide and optional metal chelating agents and isuseful for a pH range of about 8 to 10. In the present invention, a pHgreater than 10 is required to effect the desired residue removal. Inaddition, silicates have limited water solubility at about pH 10. Labtests indicated that when the pH of a tetramethylammonium silicatesolution is reduced to about 10 the solution becomes “cloudy” assilicates precipitate out of solution.

U.S. Pat. No 5,498,293 discloses a process for using an aqueous alkalinecleaning solution that contains a quaternary ammonium hydroxide andoptional metal chelating agents useful for cleaning silicon wafers. Thedisclosure of this cleaning process is for treatments to substratesbefore the presence of integrated metal circuits and is used to generatea wafer surface that is essentially silicon dioxide free and would beemployed before the use of photoresist for integrated circuitfabrication. The present invention, in contrast, focuses on the cleaningof wafers with integrated circuits present which have been photoresistcoated, etched, and oxygen plasma ashed.

None of the compositions disclosed in the prior art effectively removeall organic contamination and metal-containing residues remaining aftera typical etching process. There is, therefore, a need for strippingcompositions that clean semiconductor wafer substrates by removingmetallic and organic contamination from such substrates without damagingthe integrated circuits. Such compositions must not corrode the metalfeatures that partially comprise the integrated circuit and should avoidthe expense and adverse consequences caused by intermediate rinses.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to providecompositions useful in the microelectronics industry for cleaningsemiconductor wafer substrates.

It is another object of the present invention to provide compositionsthat remove metallic and organic contamination from semiconductor wafersubstrates without damaging the integrated circuits.

It is another object of the present invention to provide compositionsthat avoid the expense and adverse consequences caused by intermediaterinses.

It is a further object of the present invention to provide a method forcleaning semiconductor wafer substrates that removes metallic andorganic contamination from such substrates without damaging theintegrated circuits and avoids the expense and adverse consequencescaused by intermediate rinses.

These and other objects are achieved using new aqueous compositions forstripping or cleaning semiconductor wafer substrates that contain one ormore metal ion-free bases and a water-soluble metal ion-free silicate.The compositions are placed in contact with a semiconductor wafersubstrate for a time and at a temperature sufficient to clean unwantedcontaminants and/or residues from the substrate surface.

Preferably, the compositions contain one or more metal ion-free basesdissolved in water in sufficient amounts to produce a pH of about 11 orgreater and about 0.01% to about 2% by weight (calculated as SiO₂) of awater-soluble metal ion-free silicate. Any suitable base may be used inthe compositions of this invention. Preferably, the base is selectedfrom hydroxides and organic amines, most preferably quaternary ammoniumhydroxides and ammonium hydroxides.

Any suitable silicate may be used in the compositions of this invention.Preferably, the silicate is selected from quaternary ammonium silicates,most preferably tetramethyl ammonium silicate.

The compositions of the present invention may contain other componentssuch as chelating agents, organic co-solvents, titanium residue removalenhancing agents, and surfactants. Chelating agents are preferablypresent in amounts up to about 2% by weight, organic co-solvents arepreferably present in amounts up to about 20% by weight, titaniumresidue removal enhancers are preferably present in amounts up to about30% by weight, and surfactants are preferably present in amounts up toabout 0.5% by weight.

The compositions can be used to clean substrates containing integratedcircuits or can be used to clean substrates that do not containintegrated circuits. When integrated circuits are present, thecomposition removes the contaminants without damaging the integratedcircuits.

The method for cleaning semiconductor wafer substrates of the presentinvention requires that the compositions of the present invention beplaced in contact with a semiconductor wafer substrate for a time and ata temperature sufficient to clean unwanted contaminants and/or residuesfrom the substrate surface. The method includes both bath and sprayapplications. Typically, the substrate is exposed to the composition forthe appropriate time and at the appropriate temperature, rinsed usinghigh purity de-ionized water, and dried.

The compositions clean wafer substrates by removing metallic and organiccontamination. Importantly, the cleaning process does not damageintegrated circuits on the wafer substrates and avoid the expense andadverse consequences associated by intermediate rinses required in priormethods.

Other objects, advantages, and novel features of the present inventionwill become apparent in the following detailed description of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides new aqueous compositions for stripping orcleaning semiconductor wafer substrates that contain one or more metalion-free bases and a water-soluble metal ion-free silicate. Preferably,the invention provides aqueous, alkaline stripping or cleaningcompositions comprising one or more alkaline metal ion-free basecomponents in an amount sufficient to produce a solution pH of about 11or greater, preferable from about pH 11 to about pH 13, and a metalion-free water-soluble silicate concentration by weight (as SiO₂) ofabout 0.01% to about 5%, preferably from about 0.01% to about 2%.

The compositions may also contain a chelating agent in a concentrationby weight of about 0.01% to about 10%, generally from about 0.01% toabout 2%. Further optional components are water-soluble organic solventsin a concentration by weight of about 0. 1% to about 80%, generallyabout 1% to about 30%, titanium residue removal enhancers in aconcentration by weight of about 1% to about 50%, generally about 1% toabout 30%, and a water-soluble surfactant in an amount by weight ofabout 0.01% to about 1%, preferable about 0.01% to about 0.5%.

The composition is an aqueous solution containing the base, thesilicate, the optional components, if any, and water, preferably highpurity de-ionized water.

Any suitable base may be used in the compositions of the presentinvention. The bases are preferably quaternary ammonium hydroxides, suchas tetraalkyl ammonium hydroxides (including hydroxy- andalkoxy-containing alkyl groups generally of from 1 to 4 carbon atoms inthe alkyl or alkoxy group). The most preferable of these alkalinematerials are tetramethyl ammonium hydroxide andtrimethyl-2-hydroxyethyl ammonium hydroxide (choline). Examples of otherusable quaternary ammonium hydroxides include: trimethyl-3-hydroxypropylammonium hydroxide, trimethyl-3-hydroxybutyl ammonium hydroxide,trimethyl-4-hydroxybutyl ammonium hydroxide, triethyl-2-hydroxyethylammonium hydroxide, tripropyl-2-hydroxyethyl ammonium hydroxide,tributyl-2-hydroxyethyl ammonium hydroxide, dimethylethyl-2-hydroxyethylammonium hydroxide, dimethyldi(2-hydroxyethyl) ammonium hydroxide,monomethyltri(2-hydroxyethyl) ammonium hydroxide, tetraethyl ammoniumhydroxide, tetrapropyl ammonium hydroxide, tetrabutyl ammoniumhydroxide, monomethyl-triethyl ammonium hydroxide, monomethyltripropylammonium hydroxide, monomethyltributyl ammonium hydroxide,monoethyltrimethyl ammonium hydroxide, monoethyltributyl ammoniumhydroxide, dimethyldiethyl ammonium hydroxide, dimethyldibutyl ammoniumhydroxide, and the like and mixtures thereof.

Other bases that will function in the present invention include ammoniumhydroxide, organic amines particularly alkanolamines such as2-aminoethanol, 1-amino-2-propanol, 1-amino-3-propanol,2-(2-aminoethoxy)ethanol, 2-(2-aminoethylamino)ethanol,2-(2-aminoethylamino)ethylamine and the like, and other strong organicbases such as guanidine, 1,3-pentanediamine,4-aminomethyl-1,8-octanediamine, aminoethylpiperazine,4-(3-aminopropyl)morpholine, 1,2-diaminocyclohexane,tris(2-aminoethyl)amine, 2-methyl-1,5-pentanediamine and hydroxylamine.Alkaline solutions containing metal ions such as sodium or potassium mayalso be operative, but are not preferred because of the possibleresidual metal contamination that could occur. Mixtures of theseadditional alkaline components, particularly ammonium hydroxide, withthe aforementioned tetraalkyl ammonium hydroxides are also useful.

Any suitable metal ion-free silicate may be used in the compositions ofthe present invention. The silicates are preferably quaternary ammoniumsilicates, such as tetraalkyl ammonium silicate (including hydroxy- andalkoxy-containing alkyl groups generally of from 1 to 4 carbon atoms inthe alkyl or alkoxy group). The most preferable metal ion-free silicatecomponent is tetramethyl ammonium silicate. Other suitable metalion-free silicate sources for this invention may be generated in-situ bydissolving any one or more of the following materials in the highlyalkaline cleaner. Suitable metal ion-free materials useful forgenerating silicates in the cleaner are solid silicon wafers, silicicacid, colloidal silica, fumed silica or any other suitable form ofsilicon or silica. Metal silicates such as sodium metasilicate may beused but are not recommended due to the detrimental effects of metalliccontamination on integrated circuits.

The compositions of the present invention may also be formulated withsuitable metal chelating agents to increase the capacity of theformulation to retain metals in solution and to enhance the dissolutionof metallic residues on the wafer substrate. Typical examples ofchelating agents useful for this purpose are the following organic acidsand their isomers and salts: (ethylenedinitrilo)tetraacetic acid (EDTA),butylenediaminetetraacetic acid, cyclohexane-1,2-diaminetetraacetic acid(CyDTA), diethylenetriaminepentaacetic acid (DETPA),ethylenediaminetetrapropionic acid,(hydroxyethyl)ethylenediaminetriacetic acid (HEDTA),N,N,N′,N′-ethylenediaminetetra(methylenephosphonic) acid (EDTMP),triethylenetetraminehexaacetic acid (TTHA),1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (DHPTA),methyliminodiacetic acid, propylenediaminetetraacetic acid,nitrolotriacetic acid (NTA), citric acid, tartaric acid, gluconic acid,saccharic acid, glyceric acid, oxalic acid, phthalic acid, maleic acid,mandelic acid, malonic acid,lactic acid, salicylic acid, catechol,gallic acid, propyl gallate, pyrogallol, 8-hydroxyquinoline, andcysteine.

Preferred chelating agents are aminocarboxylic acids such as EDTA.Chelating agents of this class have a high affinity for thealuminum-containing residues typically found on metal lines and viasafter plasma “ashing”. In addition, the pKa's for this class ofchelating agents typically include one pKa of approximately 12 whichimproves the performance of the compositions of the invention.

The compositions of the present invention may also contain one or moresuitable water-soluble organic solvents. Among the various organicsolvents suitable are alcohols, polyhydroxy alcohols. glycols, glycolethers, alkyl-pyrrolidinones such as N-methylpyrrolidinone (NMP),1-hydroxyalkyl-2-pyrrolidinones such as1-(2-hydroxyethyl)-2-pyrrolidinone (HEP), dimethylformamide (DMF),dimethylacetamide (DMAc), sulfolane or dimethylsulfoxide (DMSO). Thesesolvents may be added to reduce aluminum and/or aluminum-copper alloyand/or copper corrosion rates if further aluminum and/or aluminum-copperalloy and/or copper corrosion inhibition is desired. Preferredwater-soluble organic solvents are polyhydroxy alcohols such as glyceroland/or 1-hydroxyalkyl-2-pyrrolidinones such as1-(2-hydroxyethyl)-2-pyrrolidinone (HEP).

The compositions of the present invention may also contain one or moresuitable titanium residue removal enhancers. Among the various titaniumresidue removal enhancers that are suitable are hydroxylamine,hydroxylamine salts, peroxides, ozone and fluoride. Preferred titaniumresidue removal enhancers are hydroxylamine and hydrogen peroxide.

The compositions of the present invention may also contain any suitablewater-soluble amphoteric, non-ionic, cationic or anionic surfactant. Theaddition of a surfactant will reduce the surface tension of theformulation and improve the wetting of the surface to be cleaned andtherefore improve the cleaning action of the composition. The surfactantmay also be added to reduce aluminum corrosion rates if further aluminumcorrosion inhibition is desired.

Amphoteric surfactants useful in the compositions of the presentinvention include betaines and sulfobetaines such as alkyl betaines,amidoalkyl betaines, alkyl sulfobetaines and amidoalkyl sulfobetaines;aminocarboxylic acid derivatives such as amphoglycinates,amphopropionates, amphodiglycinates, and amphodipropionates;iminodiacids such as alkoxyalkyl iminodiacids or alkoxyalkyliminodiacids; amine oxides such as alkyl amine oxides and alkylamidoalkylamine oxides; fluoroalkyl sulfonates and fluorinated alkylamphoterics; and mixtures thereof.

Preferably, the amphoteric surfactants are cocoamidopropyl betaine,cocoamidopropyl dimethyl betaine, cocoamidopropyl hydroxy sultaine,capryloamphodipropionate, cocoamidodipropionate, cocoamphopropionate,cocoamphohydroxyethyl propionate, isodecyloxypropylimino dipropionicacid, laurylimino dipropionate, cocoamidopropylamine oxide and cocoamineoxide and fluorinated alkyl amphoterics.

Non-ionic surfactants useful in the compositions of the presentinvention include acetylenic diols, ethoxylated acetylenic diols,fluorinated alkyl alkoxylates, fluorinated alkylesters, fluorinatedpolyoxyethylene alkanols, aliphatic acid esters of polyhydric alcohols,polyoxyethylene monoalkyl ethers, polyoxyethylene diols, siloxane typesurfactants, and alkylene glycol monoalkyl ethers. Preferably, thenon-ionic surfactants are acetylenic diols or ethoxylated acetylenicdiols.

Anionic surfactants useful in the compositions of the present inventioninclude carboxylates, N-acylsarcosinates, sulfonates, sulfates, and monoand diesters of orthophosphoric acid such as decyl phosphate.Preferably, the anionic surfactants are metal-free surfactants.

Cationic surfactants useful in the compositions of the present inventioninclude amine ethoxylates, dialkyldimethylammonium salts,dialkylmorpholinum salts, alkylbenzyldimethylammonium salts,alkyltrimethylammonium salts, and alkylpyridinium salts. Preferably, thecationic surfactants are halogen-free surfactants.

In the preferred embodiment of the present invention, the composition isan aqueous solution containing about 0.1-2% by weighttetramethylammonium hydroxide (TMAH) and about 0.01-1% by weight(calculated as % SiO₂,) tetramethylammonium silicate (TMAS).

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-2% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), and about0.01-1% by by weight (calculated as % SiO₂) tetramethylammonium silicate(TMAS).

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-2% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA),about 0.01-1%by weight (calculated as % SiO₂) tetramethylammonium silicate (TMAS),and about 0.5-20% by weight of polyhydroxy compounds, preferablyglycerol.

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-2% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), about0.01-1% by weight (calculated as % SiO₂) tetramethylammonium silicate(TMAS), about 0.5-20% by weight of polyhydroxy compounds, and about0.01-0.3% by weight of a nonionic ethoxylated acetylenic diolsurfactant.

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-2% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraactic acid (CyDTA),about 0.01-1%by weight (calculated as % SiO₂)tetramethylammonium silicate (TMAS), andabout 0.5-20% by weight of an alkyl-pyrrolidinone such as1-(2-hydroxyethyl)-2-pyrrolidinone (HEP), preferably1-(2-hydroxyethyl)-2-pyrrolidinone (HEP).

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-2% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), about0.01-1% by weight (calculated as % SiO₂) tetramethylammonium silicate(TMAS), about 0.5-20% by weight of an alkyl-pyrrolidinone such as1-(2-hydroxyethyl)-2-pyrrolidinone (HEP), and about 0.01-0.3% by weightof a nonionic ethoxylated acetylenic diol surfactant.

In a preferred embodiment of the present invention, the composition isan aqueous solution containing about 0.1-10% by weighttetramethylammonium hydroxide (TMAH), about 0.01-1% by weight(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and about1-10% by weight hydrogen peroxide.

In another preferred embodiment of the present invention, thecomposition is an aqueous solution containing about 0.1-9% by weighttetramethylammonium hydroxide (TMAH), about 0.01-4% by weight(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and about1-20% by weight hydroxylamine.

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-10% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA),about 0.01-1%by weight (calculated as % SiO₂) tetramethylammonium silicate (TMAS) andabout 1-10% by weight hydrogen peroxide.

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-9% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), about0.01-4% by weight (calculated as % SiO₂) tetramethylammonium silicate(TMAS) and about 1-20% by weight hydroxylamine.

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-10% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), about0.01-1% by weight (calculated as % SiO₂) tetramethylammonium silicate(TMAS), about 1-10% by weight hydrogen peroxide, and about 0.01-0.3% byweight of a nonionic ethoxylated acetylenic diol surfactant.

In another embodiment of the present invention, the composition is anaqueous solution containing about 0.1-9% by weight tetramethylammoniumhydroxide (TMAH), about 0.01-1% by weighttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), about0.01-4% by weight (calculated as % SiO₂) tetramethylammonium silicate(TMAS), about 1-20% by weight hydroxylamine, and about 0.01-0.3% byweight of a nonionic ethoxylated acetylenic diol surfactant.

In all the embodiments, the balance of the composition is made up withwater, preferably high purity de-ionized water.

As shown in the examples below, compositions containing only thealkaline base are unable to produce effective cleaning action withoutcorroding the aluminum metal integrated circuit features. The examplesalso show the utility of adding a soluble silicate to the highly basicformulations to (1) protect the aluminum metal integrated circuits fromcorrosion, (2) extend the solution bath life of these cleanercompositions by silicate buffering (pKa₂=11.8), and (3) decrease thesilicon dioxide dielectric etch rate. Additional advantages of thecompositions of the present invention are: (1) high water content thatfacilitates immediate rinsing with water without an intermediate (suchas isopropanol) rinse to prevent post-cleaning metal corrosion and thatresults in negligible carbon contamination of the substrate surface, (2)reduced health, safety, environmental, and handling risks associatedwith the use of non-toxic components specifically avoiding catechol,volatile organic solvents, and organic amines characteristic of priorart compositions used to strip and clean integrated circuit substrates,(3) ability to remove titanium containing residues from integratedcircuit substrates at low temperatures, (4) compatibility of theseformulations with sensitive low k dielectric materials used inintegrated circuits, (5) compatibility (low etch rates) with copper, and(6) ability of the compositions of this invention to clean and preventcontamination of a wafer substrate during a post chemical mechanicalpolishing (CMP) operation.

The method of the present invention cleans semiconductor wafersubstrates by exposing the contaminated substrate to the compositions ofthe present invention for a time and at a temperature sufficient toclean unwanted contaminants from the substrate surface. Optionally, thesubstrate is rinsed to remove the composition and the contaminants anddried to remove any excess solvents or rinsing agents. The substrate canthen be used for its intended purpose.

Preferably, the method uses a bath or spray application to expose thesubstrate to the composition. Bath or spray cleaning times are generally1 minute to 30 minutes, preferably 5 minutes to 20 minutes. Bath orspray cleaning temperatures are generally 10° C. to 85° C., preferably20° C. to 45° C.

If required, the rinse times are generally 10 seconds to 5 minutes atroom temperature, preferably 30 seconds to 2 minutes at roomtemperature. Preferably de-ionized water is used to rinse thesubstrates.

If required, drying the substrate can be accomplished using anycombination of air-evaporation, heat, spinning, or pressurized gas. Thepreferred drying technique is spinning under a filtered inert gas flow,such as nitrogen, for a period of time until the wafer substrate is dry.

The method of the present invention is very effective for cleaningsemiconductor wafer substrates that have been previously oxygen plasmaashed to remove bulk photoresist, particularly wafer substratescontaining a silicon, silicon oxide, silicon nitride, tungsten, tungstenalloy, titanium, titanium alloy, tantalum, tantalum alloy, copper,copper alloy, aluminum or aluminum alloy film. The method removesunwanted metallic and organic contaminants but does not causeunacceptable corrosion to the silicon, silicon oxide, silicon nitride,tungsten, tungsten alloy, titanium, titanium alloy, tantalum, tantalumalloy, copper, copper alloy, aluminum or aluminum alloy film.

The following examples illustrate the specific embodiment of theinvention described in this document. As would be apparent to skilledartisans, various changes and modifications are possible and arecontemplated within the scope of the invention described.

Experimental Procedures

The percentages given in the examples are by weight unless specifiedotherwise. The amount of aluminum metal corrosion is expressed as bothpercent metal loss and as a general corrosion remark. The generalcorrosion remarks given are very slight, slight, light, moderate andsevere. A small amount of aluminum corrosion considered to be withinacceptable limits were assigned very slight or slight. Light, moderateor severe corrosion were considered to be unacceptable. All cleaning andcorrosion data entries generated using the Scanning Electron Microscope(SEM) or Field Emission Scanning Electron Microscope (FE-SEM) was basedon a visual interpretation of differences between untreated and treatedsamples from the same wafer.

EXAMPLE 1

Aqueous solution “A” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 (a product of AirProducts and Chemicals, Inc.) and 0.14 weight percent (calculated as %SiO₂) tetramethylammonium silicate (TMAS) added (remainder of thissolution being water) and has a pH of about 12.2. Aqueous solution “B”was prepared with 0.3 weight percent tetramethylammonium hydroxide(TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 (remainder of thissolution being water) and has a pH of about 12.7. Aqueous solution “C”was prepared with 0.08 weight percent tetramethylammonium hydroxide(TMAH), 0.1 weight percent trans-(1,2-cyclohexylenedinitrilo)tetraaceticacid (CyDTA), 0.07 weight percent of the non-ionic surfactantSurfynol-465 and 0.13 weight percent (calculated as % SiO₂)tetramethylammonium silicate (TMAS) added (remainder of this solutionbeing water) and has a pH of about 10.5. Aqueous solution “D” wasprepared with 0.09 weight percent tetramethylammonium hydroxide (TMAH),0.1 weight percent trans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid(CyDTA), 0.07 weight percent of the non-ionic surfactant Surfynol-465(remainder of this solution being water) and has a pH of about 9.6.Aqueous solution “E” was prepared with 0.1 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 and 0.010 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 11.3Aqueous solution “F” was prepared with 0.08 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 (remainder of thissolution being water) and has a pH of about 10.9. Wafer #1 samples withone micron wide features and Aluminum-Copper raised lines capped withtitanium-nitride, that had been previously prepared as follows: (a)metallization with aluminum-copper alloy followed by titanium nitride(b) lithographic patterning using a photoresist material (c) patterntransfer using reactive ion etching (d) oxygen plasma ashing to removeorganic photoresist residues, but leaving mainly inorganic residuesbehind, were used to evaluate the performance of the solutions. A wafersample was placed in each of these solutions at 21-65° C. for 5-10minutes, removed, rinsed with de-ionized water and dried withpressurized nitrogen gas. After drying, the sample was inspected on aScanning Electron Microscope (SEM) to determine the extent of cleaningand/or corrosion of the aluminum-copper metal features. The results areshown in Table 1.

TABLE 1 SEM Evaluation Results Weight Percent Tetramethyl- ammoniumAluminum Silicate Post-Ash Metal Added Residue Corrosion (calculated as% Time Temp. Removed (% Metal Solution SiO₂) pH (min.) (° C.) (%) Loss)A 0.14 12.2 5 35 100 0 B 0 12.7 5 35 100 80 (severe) C 0.13 10.5 5 35 00 D 0 9.6 5 35 100 20 (moderate) C 0.13 10.5 5 65 2 0 D 0 9.6 5 65 10080 (severe) E 0.010 11.3 10 21 100 0 F 0 10.9 10 22 100 15 (light)

Referring to Table 1. the data show the ability of TMAS to prevent thecorrosion of the aluminum features that accompanies exposure to alkalinesolutions and show that the addition of tetramethylammonium silicate totetramethylammonium hydroxide based cleaning solutions completelyinhibits undesirable corrosion of an integrated circuit.

EXAMPLE 2

Aqueous solution “G” was prepared with 2.0 weight percenttetramethylammonium hydroxide (TMAH), 0.09 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465 and 0.13 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.6.Aqueous solution “H” was prepared with 0.09 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 and 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 10.8.Aqueous solution “M” was prepared with 1.8 weight percenttetramethylammonium hydroxide (TMAH), 0.09 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465 and 1.3 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.0.Aqueous solution “N” was prepared with 1.9 weight percenttetramethylammonium hydroxide (TMAH), 0.09 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465 and 0.86 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.2.Aqueous solution “O” was prepared with 1.9 weight percenttetramethylammonium hydroxide (TMAH), 0.09 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465 and 0.70 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.2.Aqueous solution “P” was prepared with 1.9 weight percenttetramethylammonium hydroxide (TMAH), 0.09 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465 and 0.54 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.3.Aqueous solution “Q” was prepared with 2.0 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465 and 0.45 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.3.Aqueous solution “R” was prepared with 2.0 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465 and 0.28 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.4.Aqueous solution “S” was prepared with 2.0 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent trans-(1,2-surfactant Surfynol-465 and 0.19 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 13.4.Aqueous solution “T” was prepared with 0.1 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 and 0.020 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 11.2Aqueous solution “U” was prepared with 0.1 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 and 0.070 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) added(remainder of this solution being water) and has a pH of about 10.9.Wafer #1 samples with one micron wide features and Aluminum-Copperraised lines capped with titanium-nitride, that had been previouslyprepared as follows: (a) metallization with aluminum-copper alloyfollowed by titanium nitride (b) lithographic patterning using aphotoresist material (c) pattern transfer using reactive ion etching (d)oxygen plasma ashing to remove organic photoresist residues, but leavingmainly inorganic residues behind, were used to evaluate the performanceof the solutions. A wafer sample was placed in the solution at 21-65° C.for 5-20 minutes, removed, rinsed with de-ionized water and dried withpressurized nitrogen gas. After drying, the sample was inspected on aScanning Electron Microscope (SEM) to determine the extent of cleaningand/or corrosion of the aluminum-copper metal features. The results areshown in Table 2.

TABLE 2 SEM Evaluation Results Weight Percent Tetramethyl- ammoniumAluminum Silicate Post-Ash Metal Added Residue Corrosion (calculated asTime Temp. Removed (% Metal Solution % SiO₂) pH (min.) (° C.) (%) Loss)H 0.14 10.8 20 65 0 0 U 0.070 10.9 5 35 20 0 T 0.020 11.2 10 22 95 0 E0.010 11.3 10 21 100 0 A 0.14 12.2 5 35 100 0 M 1.3 13.0 5 22 100 0 M1.3 13.0 5 35 100 10 (light) N 0.86 13.2 5 22 100 6 (light) O 0.70 13.25 22 100 8 (light) P 0.54 13.3 5 22 100 10 (light) Q 0.45 13.3 5 23 10010 (light) R 0.28 13.4 5 23 100 20 (moderate) S 0.19 13.4 5 23 100 20(moderate) G 0.13 13.6 5 35 100 90 (severe)

Referring to Table 2. the data show the need to increase the TMASconcentration as the pH is increased in order to prevent or moderate thecorrosion of the aluminum features that accompanies exposure to thesealkaline solutions and show that the optimum pH range for the solutionsof the present application is about 11 to 13.

EXAMPLE 3

Aqueous solution “T” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH). 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465, 0.13 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 5 weightpercent glycerol added with the remainder of this solution being water.Aqueous solution “J” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.09 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465, 0.13 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 6 weightpercent glycerol added with the remainder of this solution being water.Aqueous solution “K” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.09 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.06 weightpercent of the non-ionic surfactant Surfynol-465. 0.12 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 10 weightpercent diethylene glycol (DEG) added with the remainder of thissolution being water. Wafer #1 samples with one micron wide features andaluminum-copper raised lines capped with titanium-nitride that had beenpreviously prepared as follows: (a) metallization with aluminum-copperalloy followed by titanium nitride (b) lithographic patterning using aphotoresist material (c) pattern transfer using reactive ion etching (d)oxygen plasma ashing to remove organic photoresist residues, but leavingmainly inorganic residues behind were used to evaluate the performanceof the solutions. A wafer sample was placed in the solution at 21-35° C.for 5-20 minutes, removed, rinsed with de-ionized water and dried withpressurized nitrogen gas. After drying, the sample was inspected on aScanning Electron Microscope (SEM) to determine the extent of cleaningand/or corrosion of the aluminum-copper metal features. The results areshown in Table 3.

TABLE 3 SEM Evaluation Results Solvent Post-Ash Content Residue AluminumTime Temp. (Weight Removed Metal Solution (min.) (° C.) Solvent %) (%)Corrosion A 5 35 — 0 100 none A 20 21 — 0 100 slight I 15 35 Glycerol 5100 none I 20 35 Glycerol 5 100 none J 15 35 Glycerol 6 100 none K 15 35DEG 10 100 none K 20 35 DEG 10 100 none

Referring to Table 3, the data show the advantages of the addition of awater-soluble organic solvent on the ability to prevent or moderate thecorrosion of the aluminum features that accompanies exposure to alkalinesolutions containing TMAS and illustrate that the addition of awater-soluble solvent to the compositions of the present inventionallows longer cleaning times without corrosion of metal lines present inintegrated circuits.

EXAMPLE 4

Aqueous solution “L” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465, 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 3 weightpercent glycerol added with the remainder of this solution being water.Wafer sample #2 with one-half micron wide by one micron deep holes(vias) through a dielectric material exposing Aluminum-Copper metal atthe base had been previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic residues behind. Wafer sample #3 with one micron wide by onemicron deep tapered holes (vias) through a dielectric material exposingAluminum-Copper metal at the base had been previously processed asfollows (a) metallization with aluminum-copper followed by titaniumnitride (b) coated with silicon oxide dielectric using chemical vapordeposition (c) lithographic patterning of vias using a photoresistmaterial (d) pattern transfer to the dielectric layer using a reactiveion etching (e) oxygen plasma ashing to remove most of the residualphotoresist, but leaving mainly inorganic residues behind. These sampleswere used to evaluate the performance of the solutions. A wafer samplewas placed in the solution at 20-21° C. for 10 minutes, removed, rinsedwith de-ionized water and dried with pressurized nitrogen gas. Afterdrying, the sample cross-sectioned and then inspected on a ScanningElectron Microscope (SEM) to determine the extent of cleaning and/orcorrosion of the features. The results are shown in Table 4.

TABLE 4 SEM Evaluation Results Post-Ash Via-base Glycerol ResidueAluminum Solu- Sample Time Temp. Content Removed Metal tion # (min.) (°C.) (Weight %) (%) Corrosion A 2 10 20 0 100 slight L 2 10 21 3 100 noneA 3 10 21 0 100 slight L 3 10 21 3 100 none

Referring to Table 4, the data show the advantages of the addition of awater-soluble organic solvent on the ability to prevent or moderate thecorrosion of the aluminum features that accompanies exposure to alkalinesolutions containing TMAS and illustrate that the addition of awater-soluble solvent to the compositions of the present inventionallows the cleaning of vias without corrosion of metal at the base ofthe via.

EXAMPLE 5

Wafer #1 and #4 samples each with one micron wide features andAluminum-Copper raised lines capped with titanium-nitride, that had beenpreviously prepared as follows: (a) metallization with aluminum-copperalloy followed by titanium nitride (b) lithographic patterning using aphotoresist material (c) pattern transfer using reactive ion etching (d)oxygen plasma ashing to remove organic photoresist residues, but leavingmainly inorganic residues behind, were used to evaluate the performanceof the solutions. A wafer sample was placed in the solution at 11-65° C.for 5-30 minutes, removed, rinsed with de-ionized water and dried withpressurized nitrogen gas. After drying, the sample was inspected on aScanning Electron Microscope (SEM) to determine the extent of cleaningand/or corrosion of the aluminum-copper metal features. The results areshown in Tables 5A, 5B, and 5C.

TABLE 5A SEM Evaluation Results Post-Ash Aluminum Metal Sample TimeTemp. Residue Corrosion Solution # (min.) (° C.) Removed (%) (% MetalLoss) A 1 10 20 100 0 A 1 10 22 100 0 A 1 5 35 100 0 A 1 5 45 100 0

TABLE 5B SEM Evaluation Results Post-Ash Aluminum Metal Sample TimeTemp. Residue Corrosion Solution # (min.) (° C.) Removed (%) (% MetalLoss) L 1 10 35 100 2 (very slight) L 1 5 45 100 1 (very slight) L 1 1045 100 2 (very slight) L 1 15 45 100 2 (very slight) L 1 20 45 100 4(slight) L 1 5 55 100 3 (slight) L 1 5 65 100 3 (slight)

TABLE 5C SEM Evaluation Results Post-Ash Aluminum Metal Sample TimeTemp. Residue Corrosion Solution # (min.) (° C.) Removed (%) (% MetalLoss) A 4 15 11 100 0 A 4 5 20 100 0 A 4 10 20 100 1 (very slight) A 410 20 100 3 (slight) A 4 15 20 100 10 (light) A 4 20 20 100 10 (light) A4 25 20 100 10 (light) A 4 30 20 100 10 (light) A 4 5 35 100 1 (veryslight) A 4 5 45 100 1 (very slight)

Referring to Tables 5A, 5B and 5C, the data show that there isconsiderable process latitude for these formulations both with (solution“L”) and without (solution “A”) the addition of a water-soluble organicsolvent. A comparison of Tables 5B and 5C also illustrates that theaddition of a water-soluble organic solvent (solution “L”) furtherimproves the process latitude by decreasing the aluminum metal corrosionthat occurs with longer process times and higher temperatures. In Table5B, in which organic solvent was added to the formulation, the observedcorrosion range was only 0-4%, even when a cleaning temperature of 65°C. was used. In Table 5C, in which no organic solvent was added, morethan 4% corrosion was observed with cleaning times greater than 10minutes. The data also illustrate the considerable process latitudeobtained with the compositions of this invention and show that processlatitude can be further improved by the addition of optionalwater-soluble solvents.

EXAMPLE 6

Aqueous solution “V” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.07 weight percent of thenon-ionic surfactant Surfynol-465, and 0.14 weight percent (calculatedas % SiO₂) tetramethylammonium silicate (TMAS) added with the remainderof this solution being water. Aqueous solution “W” was prepared with 0.6weight percent tetramethylammonium hydroxide (TMAH), 0.3 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465, and 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) addedwith the remainder of this solution being water. Aqueous solution “X”was prepared with 0.7 weight percent tetramethylammonium hydroxide(TMAH), 0.5 weight percent trans-(1,2-cyclohexylenedinitrilo)tetraaceticacid (CyDTA), 0.07 weight percent of the non-ionic surfactantSurfynol-465, and 0.14 weight percent (calculated as % SiO₂)tetramethylammonium silicate (TMAS) added with the remainder of thissolution being water. Wafer #4 samples with one micron wide features andAluminum-Copper raised lines capped with titanium-nitride, that had beenpreviously prepared as follows: (a) metallization with aluminum-copperalloy followed by titanium nitride (b) lithographic patterning using aphotoresist material (c) pattern transfer using reactive ion etching (d)oxygen plasma ashing to remove organic photoresist residues, but leavingmainly inorganic residues behind, were used to evaluate the performanceof the solutions. A wafer sample was placed in the solution at 20-21° C.for 5 minutes, removed, rinsed with de-ionized water and dried withpressurized nitrogen gas. After drying, the sample was inspected on aScanning Electron Microscope (SEM) to determine the extent of cleaningand/or corrosion of the aluminum-copper metal features. The results areshown in Table 6.

TABLE 6 SEM Evaluation Results Via-base CyDTA Post-Ash Aluminum TimeTemp. Content Residue Metal Solution (min.) (° C.) (Weight %) Removed(%) Corrosion V 5 21 0 100 none A 5 20 0.1 100 none W 5 20 0.3 100 veryslight X 5 21 0.5 100 none

Referring to Table6, the data show that good stripping performance canbe obtained over a wide range of CyDTA concentrations. Thus, the amountof chelating agent present can be adjusted to accommodate the sample tobe cleaned. More difficult samples may require this optional ingredientto accomplish complete cleaning. The data also illustrate the optionaluse of a chelating agent in the compositions disclosed herein.

EXAMPLE 7

Aqueous solution “Y” was prepared with 0.4 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), and 0.14weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water. Wafer #4samples with one micron wide features and Aluminum-Copper raised linescapped with titanium-nitride, that had been previously prepared asfollows: (a) metallization with aluminum-copper alloy followed bytitanium nitride (b) lithographic patterning using a photoresistmaterial (c) pattern transfer using reactive ion etching (d) oxygenplasma ashing to remove organic photoresist residues, but leaving mainlyinorganic residues behind, were used to evaluate the performance of thesolutions. A wafer sample was placed in the solution at 20-21° C. for 5minutes, removed, rinsed with de-ionized water and dried withpressurized nitrogen gas. After drying, the sample was inspected on aScanning Electron Microscope (SEM) to determine the extent of cleaningand/or corrosion of the aluminum-copper metal features. The results areshown in Table 7.

TABLE 7 SEM Evaluation Results Surfactant Via-base Surfynol-465 Post-AshAluminum Time Temp. Content Residue Metal Solution (min.) (° C.) (Weight%) Removed (%) Corrosion A 5 20 0.07 100 none Y 5 21 0 100 none

Referring to Table 7, the data show that good stripping performance canbe obtained for formulations that incorporate a surfactant to improvethe wetting of the substrate and illustrate the optional use of asurfactant in the compositions disclosed herein.

EXAMPLE 8

Standard baths were used to perform open bath aging experiments on twodifferent formulations. The first bath was run at room temperature for24.75 hours and the second bath was run for 24.75 hours at 45° C. Wafer#4 samples with one micron wide features and Aluminum-Copper raisedlines capped with titanium-nitride, that had been previously prepared asfollows: (a) metallization with aluminum-copper alloy followed bytitanium nitride (b) lithographic patterning using a photoresistmaterial (c) pattern transfer using reactive ion etching (d) oxygenplasma ashing to remove organic photoresist residues, but leaving mainlyinorganic residues behind, were used to evaluate the performance of thesolutions. A wafer sample was placed in the bath at 20° C. or 45° C. for10 minutes, removed, rinsed with de-ionized water and dried withpressurized nitrogen gas. After drying, the sample was inspected on aScanning Electron Microscope (SEM) to determine the extent of cleaningand/or corrosion of the aluminum-copper metal features. The results areshown in Table 8.

TABLE 8 SEM Evaluation Results Post-Ash Open Residue Aluminum Bath AgeSolution Time Temp. Removed Metal Solution (Hours) pH (min.) (° C.) (%)Corrosion A 0 12.2 10 20 100 none A 24.75 12.0 10 20 100 none L 0 12.010 45 100 none L 24.75 11.9 10 45 100 none

Referring to Table 8, the data show the benefits of silicate bufferingduring extended time open-bath aging at both room temperature and at anelevated temperature. No change in stripping performance occurred duringthis aging period. The data also illustrate the insensitivity to agingof the compositions of this invention.

EXAMPLE 9

Aqueous solution “A1” was prepared with 0.27 weight percenttetramethylammonium hydroxide (TMAH) and 0.14 weight percent (calculatedas % SiO₂) tetramethylammonium silicate (TMAS) added with the remainderof this solution being water (solution pH=12.3). Aqueous solution “A2”was prepared with 0.38 weight percent tetramethylammonium hydroxide(TMAH), 0.09 weight percent of the chelating agent(ethylenedinitrilo)tetraacetic acid (EDTA) and 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added withthe remainder of this solution being water (solution pH=12.3). Aqueoussolution “A3” was prepared with 0.39 weight percent tetramethylammoniumhydroxide (TMAH), 0.10 weight percent of the chelating agentdiethylenetriaminepentaacetic acid (DETPA) and 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added withthe remainder of this solution being water (solution pH=12.3). Aqueoussolution “A4” was prepared with 0.40 weight percent tetramethylammoniumhydroxide (TMAH), 0.10 weight percent of the chelating agenttriethylenetetraminehexaacetic acid (TTHA) and 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added withthe remainder of this solution being water (solution pH=12.3). Aqueoussolution “A5” was prepared with 0.40 weight percent tetramethylammoniumhydroxide (TMAH), 0.10 weight percent of the chelating agent1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (DHPTA) and 0.14weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.3). Aqueous solution “A6” was prepared with 0.47 weight percenttetramethylammonium hydroxide (TMAH), 0.13 weight percent of thechelating agent N,N,N′,N′-ethylenediaminetetra(methylenephosphonic acid)(EDTMP) and 0.14 weight percent (calculated as % SiO₂)tetramethylammonium silicate (TMAS) added with the remainder of thissolution being water (solution pH=12.3). Each solution was placed into a125 ml glass bottle, loosely capped and placed into a oven set at 45° C.for one hour. A 0.05 mm×12 mm×50 mm, 99.8% pure aluminum foil coupon waswashed with acetone, dried, then weighed on an analytical balance. Afterone hour of pre-heating each solution was removed from the oven and thealuminum foil coupon was then placed into the bottle, loosely re-cappedand placed back into the oven. After one hour at about 45° C., thebottle was removed from the oven. The aluminum coupon was removed,rinsed with water, followed by an acetone rinse, dried and then weighedon an analytical balance. The relative corrosion rates were determinedby weight loss. The results are shown in Table 9.

TABLE 9 Aluminum Foil Etch Rate Comparisons Amount of Relative ChelatingAgent Aluminum Chelating Agent Added Corrosion Solution pH Tested(Weight %) Rate A1 12.3 — 0 1 A2 12.3 EDTA 0.090 3.5 A3 12.3 DETPA 0.103.4 A4 12.3 TTHA 0.10 3.3 A5 12.3 DHPTA 0.10 3.4 A6 12.3 EDTMP 0.13 4.0

Referring to Table 9, the data show the utility of adding a chelatingagent to accelerate aluminum etching rates. Increased aluminum etchingrates are sometimes needed to enable the removal of the metallicresidues found on post oxygen plasma ashed wafers in an acceptablestripping temperature and time range. The data also illustrate the useof optional chelating agents with varied structures to obtain adesirable aluminum etching rate for the compositions invented herein.

EXAMPLE 10

Aqueous solution “B1” was prepared with 0.22 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), and 0.14weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.3). Aqueous solution “B2” was prepared with 0.30 weight percenttetramethylammonium hydroxide (TMAH), 0.10 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), and 0.14weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.3). Aqueous solution “B3” was prepared with 0.45 weight percenttetramethylammonium hydroxide (TMAH), 0.30 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), and 0.14weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.2). Aqueous solution “B4” was prepared with 0.59 weight percenttetramethylammonium hydroxide (TMAH), 0.50 weight percenttrans-(1,2-cyclohexylenedinitrilo) tetraacetic acid (CyDTA), and 0.14weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.1). Aqueous solution “B5” was prepared with 1.1 weight percenttetramethylammonium hydroxide (TMAH), 1.0 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), and 0.14weight percent (calculated as % SiO₂,) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.3). Aqueous solution “B6” was prepared with 4.1 weight percenttetramethylammonium hydroxide (TMAH), 4.8 weight percenttrans-(1,2-cyclohexylenedinitrilo) tetraacetic acid (CyDTA), and 0.13weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.3). Each solution was placed into a 125 ml polyethylene bottle,loosely capped and placed into a oven set at 45° C. for one hour. A 0.05mm×12 mm×50 mm, 99.8% pure aluminum foil coupon was washed with acetone,dried, then weighed on an analytical balance. After one hour ofpre-heating each solution was removed from the oven and the aluminumfoil coupon was then placed into the bottle, loosely re-capped andplaced back into the oven. After one hour at about 45° C., the bottlewas removed from the oven. The aluminum coupon was removed, rinsed withwater, followed by an acetone rinse, dried and then weighed on ananalytical balance. The relative corrosion rates were determined byweight loss. The results are shown in Table 10.

TABLE 10 Aluminum Foil Etch Rate Comparisons Amount of RelativeChelating Agent Aluminum Chelating Agent Added Corrosion Solution pHTested (Weight %) Rate B1 12.3 — 0 1 B2 12.3 CyDTA 0.10 3.7 B3 12.2CyDTA 0.30 3.9 B4 12.1 CyDTA 0.50 4.0 B5 12.3 CyDTA 1.0 12 B6 12.3 CyDTA4.8 16

Referring to Table 10, the data show the utility of adding a chelatingagent to accelerate aluminum etching rates. Increased aluminum etchingrates are sometimes needed to enable the removal of the metallicresidues found in post oxygen plasma ashed wafers in an acceptablestripping temperature and time range. The aluminum etching rate isproportional to the amount of chelating agent used. The data alsoillustrate the use of an optional chelating agent, added at variousconcentrations, to obtain a desirable aluminum etching rate for thecompositions invented herein.

EXAMPLE 11

Aqueous solution “C1” was prepared with 0.25 weight percenttetramethylammonium hydroxide (TMAH) and 0.14 weight percent (calculatedas % SiO₂) tetramethylammonium silicate (TMAS) added with the remainderof this solution being water (solution pH=12.3). Aqueous solution “C2”was prepared with 0.36 weight percent choline and 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added withthe remainder of this solution being water (solution pH=12.3). Aqueoussolution “C3” was prepared with 0.76 weight percent tetrabutylammoniumhydroxide (TBAH) and 0.14 weight percent (calculated as % SiO₂)tetramethylammonium silicate (TMAS) added with the remainder of thissolution being water (solution pH=12.3). Aqueous solution “C4” wasprepared with 1.6 weight percent methyltriethanolammonium hydroxide(MAH) and 0.14 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) added with the remainder of this solution being water(solution pH=12.3) Aqueous solution “C5” was prepared with 0.36 weightpercent methyltriethylammonium hydroxide (MTEAH) and 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) added withthe remainder of this solution being water (solution pH=12.3). Eachsolution was placed into a 125 ml glass bottle, loosely capped andplaced into a oven set at 45° C. for one hour. A 0.05 mm×12 mm×50 mm,99.8% pure aluminum foil coupon was washed with acetone, dried, thenweighed on an analytical balance. After one hour of pre-heating eachsolution was removed from the oven and the aluminum foil coupon was thenplaced into the bottle, loosely re-capped and placed back into the oven.After one hour at about 45° C. the bottle was removed from the oven. Thealuminum coupon was removed, rinsed with water, followed by to anacetone rinse, dried and then weighed on an analytical balance. Therelative corrosion rates were determined by weight loss. The results areshown in Table 11.

TABLE 11 Aluminum Foil Etch Rate Comparisons Amount of Relative BaseAluminum Base Added Corrosion Solution pH Tested (Weight %) Rate C1 12.3TMAH 0.25 1 C2 12.3 Choline 0.36 3.7 C3 12.3 TBAH 0.76 2.1 C4 12.3 MAH1.6 4.6 C5 12.3 MTEAH 0.36 2.4

Referring to Table 11, the data show that that different metal ion-freebases may be substituted for TMAH to give enhanced aluminum etchingrates. Increased aluminum etching rates are sometimes needed to enablethe removal of the metallic residues found in post oxygen plasma ashedwafers in an acceptable stripping temperature and time range. The dataalso illustrate the use of metal ion-free alkaline components withvaried structures to obtain a desirable aluminum etching rate for thecompositions invented herein.

EXAMPLE 12

Aqueous solution “D1” was prepared with 0.14 weight percenttetramethylammonium hydroxide (TMAH) added with the remainder of thissolution being water (solution pH=12.3). Aqueous solution “D2” wasprepared with 0.25 weight percent tetramethylammonium hydroxide and 0.14weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) added with the remainder of this solution being water (solutionpH=12.3). Aqueous solution “D3” was prepared with 1.2 weight percenttetramethylammonium hydroxide (TMAH) and 1.3 weight percent (calculatedas % SiO₂) tetramethylammonium silicate (TMAS) added with the remainderof this solution being water (solution pH=12.6). Aqueous solution “D4”was prepared with 1.8 weight percent tetramethylammonium hydroxide(TMAH) and 2.8 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) added with the remainder of this solution being water(solution pH=12.6). Each solution was placed into a 125 ml glass bottle,loosely capped and placed into a oven set at 45° C. for one hour. A 0.05mm×12 mm×50 mm, 99.8% pure aluminum foil coupon was washed with acetone,dried, then weighed on an analytical balance. After one hour ofpre-heating each solution was removed from the oven and the aluminumfoil coupon was then placed into the bottle, loosely re-capped andplaced back into the oven. After one hour at about 45° C. the bottle wasremoved from the oven. The aluminum coupon was removed, rinsed withwater, followed by an acetone rinse, dried and then weighed on ananalytical balance. The relative corrosion rates were determined byweight loss. The results are shown in Table 12.

TABLE 12 Aluminum Foil Etch Rate Comparisons Amount of Relative TMASAluminum Base Added Corrosion Solution pH Used (Weight % as SiO₂) RateD1 12.3 TMAH 0 1 D2 12.3 TMAH 0.14 0.25 D3 12.6 TMAH 1.3 0.003 D4 12.6TMAH 2.8 0

Referring to Table 12, the data show that that the addition of asilicate to a metal ion-free basic solution inhibits the corrosion ofaluminum metal and illustrate the use of a metal ion-free silicate,added at various concentrations, to obtain a desirable aluminum etchingrate for the compositions invented herein.

EXAMPLE 13

Aqueous solution “E1” was prepared with 0.22 weight percenttetramethylammonium hydroxide (TMAH) and 0.14 weight percent (calculatedas % SiO₂) tetramethylammonium silicate (TMAS) added with the remainderof this solution being water (solution pH=12.2). Aqueous solution “E2”was prepared with 0.22 weight percent tetramethylammonium hydroxide(TMAH), 0.14 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) and 2.9 weight percent glycerol added with the remainderof this solution being water (solution pH=12.1). Aqueous solution “E3”was prepared with 0.20 weight percent tetramethylammonium hydroxide(TMAH), 0.13 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) and 9.1 weight percenttriethyleneglycol-monomethyl-ether added with the remainder of thissolution being water (solution pH=12.2). Aqueous solution “E4” wasprepared with 0.19 weight percent tetramethylammonium hydroxide (TMAH),0.12 weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) and 13 weight percent N-methyl-pyrrolidinone added with theremainder of this solution being water (solution pH=12.2). Aqueoussolution “E5” was prepared with 0.19 weight percent tetramethylammoniumhydroxide (TMAH), 0.12 weight percent (calculated as % SiO₂)tetramethylammonium silicate (TMAS) and 17 weight percent diethyleneglycol added with the remainder of this solution being water (solutionpH=12.1). Aqueous solution “E6” was prepared with 0.17 weight percenttetramethylammonium hydroxide (TMAH), 0.11 weight percent (calculated as% SiO₂) tetramethylammonium silicate (TMAS) and 23 weight percentisopropyl alcohol added with the remainder of this solution being water(solution pH=12.7). Each solution was placed into a 125 ml polyethylenebottle, loosely capped and placed into a oven set at 45° C. for onehour. A 0.05 mm×12 mm×50 mm, 99.8% pure aluminum foil coupon was washedwith acetone, dried, then weighed on an analytical balance. After onehour of pre-heating each solution was removed from the oven and thealuminum foil coupon was then placed into the bottle, loosely re-cappedand placed back into the oven. After one hour at about 45° C. the bottlewas removed from the oven. The aluminum coupon was removed, rinsed withwater, followed by an acetone rinse, dried and then weighed on ananalytical balance. The relative corrosion rates were determined byweight loss. The results are shown in Table 13.

TABLE 13 Aluminum Foil Etch Rate Comparisons Amount of Organic RelativeSolvent Aluminum Organic Solvent Added Corrosion Solution pH Tested(Weight %) Rate E1 12.2 — 0 1 E2 12.1 Glycerol 2.9 0.90 E3 12.2Triethyleneglycol monomethyl ether 9.1 0.34 E4 12.2N-Methyl-pyrrolidinone 13 0.21 E5 12.1 Diethylene glycol 17 0.21 E6 12.7Isopropanol 23 0.14

Referring to Table 13, the data show the utility of adding water-solubleorganic solvents to decrease aluminum etching rates. Decreased aluminumetching rates are sometimes needed to completely avoid aluminumcorrosion during the stripping process. The aluminum etching rate isinversely proportional to the amount of solvent used, regardless ofsolvent classification. A wide variety of water-soluble solvent typesare illustrated below. The data also illustrate the use of optionalwater-soluble organic solvents of various types to obtain a desirablealuminum etching rate for the compositions invented herein.

EXAMPLE 14

Aqueous solution “G1” was prepared with 0.22 weight percenttetramethylammonium hydroxide (TMAH) and 0.14 weight percent (calculatedas % SiO₂) tetramethylammonium silicate (TMAS) added with the remainderof this solution being water (solution pH=12.2).

Aqueous solution “G2” was prepared with 0.22 weight percenttetramethylammonium hydroxide (TMAH), 0.14 weight percent (calculated as% SiO₂) tetramethylammonium silicate (TMAS) and 0.10 weight percent ofthe nonionic surfactant Surfynol-465 added with the remainder of thissolution being water (solution pH=12.2). Aqueous solution “G3” wasprepared with 0.22 weight percent tetramethylammonium hydroxide (TMAH),0.14 weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) and 0.10 weight percent of the nonionic surfactant FluoradFC-170C (a product of the Industrial Chemical Products Division of 3M)added with the remainder of this solution being water (solutionpH=12.2). Aqueous solution “G4” was prepared with 0.22 weight percenttetramethylammonium hydroxide (TMAH), 0.14 weight percent (calculated as% SiO₂) tetramethylammonium silicate (TMAS) and 0.042 (active) weightpercent of the amphoteric surfactant Rewoteric AM KSF-40 (a product ofWitco Corporation) added with the remainder of this solution being water(solution pH=12.2). Aqueous solution “G5” was prepared with 0.22 weightpercent tetramethylammonium hydroxide (TMAH), 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 0.026(active)weight percent of the anionic surfactant Fluorad FC-93 (aproduct of the Industrial Chemical Products Division of 3M) added withthe remainder of this solution being water (solution pH=12.2). Aqueoussolution “G6” was prepared with 0.22 weight percent tetramethylammoniumhydroxide (TMAH), 0.14 weight percent (calculated as % SiO₂)tetramethylammonium silicate (TMAS) and 0.037 (active)weight percent ofthe cationic surfactant Barquat CME-35 (a product of Lonza, Inc.) addedwith the remainder of this solution being water (solution pH=12.2). Eachsolution was placed into a 125 ml polyethylene bottle, loosely cappedand placed into a oven set at 45° C. for one hour. A 0.05 mm×12 mm×50mm. 99.8% pure aluminum foil coupon was washed with acetone, dried, thenweighed on an analytical balance. After one hour of pre-heating eachsolution was removed from the oven and the aluminum foil coupon was thenplaced into the bottle, loosely re-capped and placed back into the oven.After one hour at about 45° C., the bottle was removed from the oven.The aluminum coupon was removed, rinsed with water, followed by anacetone rinse, dried and then weighed on an analytical balance. Therelative corrosion rates were determined by weight loss. The results areshown in Table 14.

TABLE 14 Aluminum Foil Etch Rate Comparisons Amount of Active RelativeSurfactant Aluminum Surfactant Surfactant Added Corrosion Solution pHTested Type (Weight %) Rate G1 12.2 — — 0 1 G2 12.2 Surfynol-465nonionic 0.10 0.62 G3 12.2 FC-170C nonionic 0.10 0.75 G4 12.2 KSF-40amphoteric 0.042 0.37 G5 12.2 FC-93 anionic 0.026 0.37 G6 12.2 CME-35cationic 0.037 0

Referring to Table 14, the data show the utility of adding a surfactantto decrease aluminum etching rates. Decreased aluminum etching rates aresometimes needed to completely avoid aluminum corrosion during thestripping process. Useful aluminum etching rate suppression occurs forall four surfactant classifications. This is in addition to the expecteddesirable feature of improved sample wetting when a surfactant ispresent. The data also illustrate the use of optional surfactants ofvarious types to obtain a desirable aluminum etching rate for thecompositions invented herein.

EXAMPLE 15

Aqueous solution “F1” was prepared with 0.20 weight percenttetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA) and 0.07weight percent of the nonionic surfactant Surfynol-465 added with theremainder of this solution being water (solution pH=12.3). Aqueoussolution “F2” was prepared with 0.30 weight percent tetramethylammoniumhydroxide (TMAH), 0.10 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and0.07 weight percent of the nonionic surfactant Surfynol-465 added withthe remainder of this solution being water (solution pH=12.3). Aqueoussolution “F3” was prepared with 0.29 weight percent tetramethylammoniumhydroxide (TMAH), 0.10 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 3.0weight percent glycerol and 0.07 weight percent of the nonionicsurfactant Surfynol-465 added with the remainder of this solution beingwater (solution pH=12.1). Sections from the same Si(100) wafer withapproximately 650 nm of thermal oxide were washed with acetone, dried,then measured with a Rudolph FTM Interferometer to determine the thermaloxide thickness. Four areas were measured and mapped for a follow-upmeasurement after treatment. Each sample was then placed into thebottle. loosely re-capped and placed into the oven, which was pre-set to45° C. After 24 hours at about 45° C., the bottle was removed from theoven, sample removed, rinsed with water, followed by an acetone rinse,dried and then measured on the Interferometer. The relative corrosionrates were determined by the difference in thermal oxide film thicknessaveraged for four areas on the sample. The results are shown in Table15.

TABLE 15 Thermal Oxide on Silicon Etch Rate Comparisons Amount ofRelative Amount of Organic Average Tetramethylammonium Co-solventThermal Oxide Solu- Silicate Added to Solution Added Corrosion tion pH(Weight % as SiO₂) (Weight %) Rate F1 12.3 — 0 1 F2 12.3 0.14 0 0.54 F312.1 0.14 3 0.50

Referring to Table 15, the data show the advantage of the adding asilicate to prevent or moderate the corrosion of silicon dioxide thataccompanies exposure to alkaline solutions. Silicon dioxide dielectricsare normally present on the integrated circuit surface during thestripping of metal lines or vias. Damage to these dielectrics must beavoided. The data also show that the addition of tetramethylammoniumsilicate to tetramethylammonium hydroxide based cleaning solutionsinhibits the undesirable corrosion of a dielectric material that iscommonly present in integrated circuits.

EXAMPLE 16

Residual organic contamination after cleaning was measured usingSecondary Ion Mass Spectroscopy (SIMS). Silicon wafer samples that weresputtered with 0.35 micron films of aluminum-1% copper alloy werecleaned with silicate solution “A” and also with a commercial post etchresidue remover, EKC-265™ (a product of EKC Technology, Inc.). EKC-265™comprises about 5% of catechol, 15%-20% each of hydroxylamine and water,and the balance being 2-(2-aminoethoxy)ethanol. A wafer sample wasplaced into solution “A” at 35° C. for 5 minutes, followed by a 2 minute0.2 micron filtered de-ionized water rinse and pressurized nitrogen dry.A second wafer sample was similarly processed in EKC-265™, using thetime and temperature recommended by the manufacturer. A third untreatedwafer piece. also from the same silicon wafer, was used as a control.The wafer samples were then analyzed by Dynamic-SIMS using an etch rateof 22.1 Angstroms per second with a dwell time of 0.5 seconds. Theatomic abundance of the carbon-12 ejected from the surface was then usedto compare carbon surface contamination of the three samples. Theresults are shown in Table 16.

TABLE 16 Relative Comparison of Residual Carbon Left on the Surface of aWafer After Cleaning Relative Time Temp. Carbon Contamination LeftSolution (Min.) (° C.) After Cleaning Untreated — — 1 A  5 35 1.1EKC-265 ™ 20 65 4.1

Referring to Table 16, the data show the superiority of the presentinvention for giving a surface free of organic contamination aftercleaning and illustrate that the use of the compositions describedherein results in very little contamination of the integrated circuitwith carbon-containing (organic) impurities.

EXAMPLE 17

Aqueous solution “H1” was prepared with 0.27 weight percenttetramethylammonium hydroxide (TMAH), 0.092 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.062 weightpercent of the non-ionic surfactant Surfynol-465, 0.13 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 2.7weight percent glycerol added with the remainder of this solution beingwater. Aqueous solution “H2” was prepared with 0.28 weight percenttetramethylammonium hydroxide (TMAH), 0.097 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.065 weightpercent of the non-ionic surfactant Surfynol-465, 0.13 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 2.9weight percent glycerol added with the remainder of this solution beingwater. Aqueous solution “H3” was prepared with 0.32 weight percenttetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.075 weightpercent of the non-ionic surfactant Surfynol-465, 0.15 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 3.3weight percent glycerol added with the remainder of this solution beingwater. Aqueous solution “H4” was prepared with 0.39 weight percenttetramethylarnmonium hydroxide (TMAH), 0.14 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.091 weightpercent of the non-ionic surfactant Surfynol-465, 0.19 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 4.0weight percent glycerol added with the remainder of this solution beingwater. Aqueous solution “H5” was prepared with 0.58 weight percenttetramethylammonium hydroxide (TMAH), 0.20 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.14 weightpercent of the non-ionic surfactant Surfynol-465, 0.28 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 6.0weight percent glycerol added with the remainder of this solution beingwater. Aqueous solution “H6” was prepared with 1.2 weight percenttetramethylammonium hydroxide (TMAH), 0.41 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.27 weightpercent of the non-ionic surfactant Surfynol-465. 0.56 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 12 weightpercent glycerol added with the remainder of this solution being water.Aqueous solution “H7” was prepared with 5.1 weight percenttetramethylarnmonium hydroxide (TMAH), 1.8 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 2.4 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and52 weight percent glycerol added with the remainder of this solutionbeing water. Wafer #5 and #6 samples with one micron wide features andAluminum-Copper raised lines capped with titanium-nitride, that had beenpreviously prepared as follows: (a) metallization with aluminum-copperalloy followed by titanium nitride (b) lithographic patterning using aphotoresist material (c) pattern transfer using reactive ion etching (d)oxygen plasma ashing to remove organic photoresist residues, but leavingmainly inorganic residues behind, were used to evaluate the performanceof the solutions. Wafer samples #7 and #8 with one-half micron wide byone micron deep holes (vias) through a dielectric material exposingAluminum-Copper metal at the base had been previously processed asfollows (a) metallization with aluminum-copper followed by titaniumnitride (b) coated with silicon oxide dielectric using chemical vapordeposition (c) lithographic patterning of vias using a photoresistmaterial (d) pattern transfer to the dielectric layer using a reactiveion etching (e) oxygen plasma ashing to remove most of the residualphotoresist, but leaving mainly inorganic residues behind. Wafer sample#9 with one micron wide by one micron deep tapered holes (vias) througha dielectric material exposing Aluminum-Copper metal at the base hadbeen previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic residues behind. A wafer sample was placed in the solution at21-45° C. for 5-10 minutes, removed, rinsed with de-ionized water anddried with pressurized nitrogen gas. After drying, the sample wasinspected on a Scanning Electron Microscope (SEM) to determine theextent of cleaning and/or corrosion of the aluminum-copper metalfeatures. The results are shown in Tables 17A-17E.

TABLE 17A SEM Evaluation Results for Sample #5 Time/ Surf.- Post-AshVia-base Temp. TMAH TMAS 465 Residue Aluminum (min./ (Wt. (Wt. %Glycerol CyDTA (Wt. Removed Metal Solution ° C.) pH %) as SiO₂) (Wt. %)(Wt. %) %) (%) Corrosion H1 5/21 12.1 0.27 0.13 2.7 0.092 0.062 100 noneH3 5/22 12.1 0.32 0.15 3.3 0.11 0.075 100 none H4 5/22 12.2 0.39 0.194.0 0.14 0.091 100 none H5 5/22 12.3 0.58 0.28 6.0 0.20 0.14 100 none H65/22 12.5 1.2 0.56 12 0.41 0.27 100 none H7 5/21 13.0 5.1 2.4 52 1.8 0100 none

TABLE 17B SEM Evaluation Results for Sample #6 Time/ Surf.- Post-AshVia-base Temp. TMAH TMAS 465 Residue Aluminum (min./ (Wt. (Wt. %Glycerol CyDTA (Wt. Removed Metal Solution ° C.) pH %) as SiO₂) (Wt. %)(Wt. %) %) (%) Corrosion H1 10/45 12.1 0.27 0.13 2.7 0.092 0.062 100very slight H3 10/45 12.1 0.32 0.15 3.3 0.11 0.075 100 very slight H410/45 12.2 0.39 0.19 4.0 0.14 0.091 100 very slight H5  5/45 12.3 0.580.28 6.0 0.20 0.14 100 very slight H6  5/45 12.5 1.2 0.56 12 0.41 0.27100 very slight H7 10/45 13.0 5.1 2.4 52 1.8 0 100 none

TABLE 17C SEM Evaluation Results for Sample #7 Time/ Surf.- Post-AshVia-base Temp. TMAH TMAS 465 Residue Aluminum (min./ (Wt. (Wt. %Glycerol CyDTA (Wt. Removed Metal Solution ° C.) pH %) as SiO₂) (Wt. %)(Wt. %) %) (%) Corrosion H1 10/21 12.1 0.27 0.13 2.7 0.092 0.062 100very slight H3 10/22 12.1 0.32 0.15 3.3 0.11 0.075 100 very slight H410/22 12.2 0.39 0.19 4.0 0.14 0.091 100 very slight H5 10/22 12.3 0.580.28 6.0 0.20 0.14 100 very slight H6 10/22 12.5 1.2 0.56 12 0.41 0.27100 very slight H7 10/21 13.0 5.1 2.4 52 1.8 0 100 very slight

TABLE 17D SEM Evaluation Results for Sample #8 Time/ Surf.- Post-AshVia-base Temp. TMAH TMAS 465 Residue Aluminum (min./ (Wt. (Wt. %Glycerol CyDTA (Wt. Removed Metal Solution ° C.) pH %) as SiO₂) (Wt. %)(Wt. %) %) (%) Corrosion H1 10/45 12.1 0.27 0.13 2.7 0.092 0.062 85slight H2 10/45 12.1 0.28 0.13 2.9 0.097 0.065 100 slight H3 10/45 12.10.32 0.15 3.3 0.11 0.075 100 slight H4 10/45 12.2 0.39 0.19 4.0 0.140.091 100 slight H5 10/45 12.3 0.58 0.28 6.0 0.20 0.14 100 slight H610/45 12.5 1.2 0.56 12 0.41 0.27 100 slight H7 10/45 13.0 5.1 2.4 52 1.80 100 slight

TABLE 17E SEM Evaluation Results for Sample #9 Time/ Surf.- Post-AshVia-base Temp. TMAH TMAS 465 Residue Aluminum (min./ (Wt. (Wt. %Glycerol CyDTA (Wt. Removed Metal Solution ° C.) pH %) as SiO₂) (Wt. %)(Wt. %) %) (%) Corrosion H1 10/23 12.1 0.27 0.13 2.7 0.092 0.062 99.5slight H2 10/23 12.1 0.28 0.13 2.9 0.097 0.065 99.2 slight H3 10/22 12.10.32 0.15 3.3 0.11 0.075 100 very slight H4 10/22 12.2 0.39 0.19 4.00.14 0.091 100 none H5 10/22 12.3 0.58 0.28 6.0 0.20 0.14 100 none H610/22 12.5 1.2 0.56 12 0.41 0.27 100 none H7 10/21 13.0 5.1 2.4 52 1.8 095 very slight

Referring to Tables 17A-17E, the data show that by varying the pH andconcentrations of each of the components allowed seven differentformulations to successfully clean residues from several differentoxygen plasma-ashed wafer samples without unacceptable aluminumcorrosion occurring.

EXAMPLE 18

Aqueous solution “H8” was prepared with 5.1 weight percenttetramethylammonium hydroxide (TMAH), 1.8 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 2.4 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and52 weight percent dimethyl sulfoxide (DMSO) added with the remainder ofthis solution being water. Aqueous solution “H9” was prepared with 0.58weight percent tetramethylammonium hydroxide (TMAH), 0.20 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.14 weightpercent of the non-ionic surfactant Surfynol-465. 0.28 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 6.0weight percent glycerol added with the remainder of this solution beingwater. Aqueous solution “H10” was prepared with 0.88 weight percenttetramethylammonium hydroxide (TMAH), 0.30 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.20 weightpercent of the non-ionic surfactant Surfynol-465, 0.42 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 9.0weight percent glycerol added with the remainder of this solution beingwater. Wafer sample #10 with one micron wide by two micron deep holes(vias) through a photoresist and dielectric material exposingAluminum-Copper metal at the base had been previously processed asfollows (a) metallization with aluminum-copper followed by titaniumnitride (b) coated with silicon oxide dielectric using chemical vapordeposition (c) lithographic patterning of vias using an approximatelyone micron thick layer of photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) Hard-bake ofphotoresist at high temperature to remove solvents, but leaving a mainlyorganic photoresist layer behind. This sample were used to evaluate theperformance of the solutions below. A wafer sample was placed in thesolution at 45-65° C. for 20-30 minutes, removed, rinsed with de-ionizedwater and dried with pressurized nitrogen gas. After drying, the samplewas inspected on a Scanning Electron Microscope (SEM) to determine theextent of cleaning and/or corrosion of the features. The results areshown in Table 18.

TABLE 18 SEM Evaluation Results Photoresist Via-base Organic Co-SolventResidue Aluminum Time Temp. Co-Solvent Content Removed Metal Solution(min.) (° C.) Used (Weight %) (%) Corrosion L 20 45 Glycerol 3.0 85 noneH9 30 65 Glycerol 6.0 88 none H10 30 65 Glycerol 9.0 88 none H6 20 65Glycerol 12 88 none H7 10 45 Glycerol 52 88 none H7 20 45 Glycerol 52 90none H7 30 65 Glycerol 52 92 none H8 30 65 DMSO 52 100 slight

Referring to Table 18, the data demonstrates the ability of thisinvention to clean an organic photoresist layer from a semiconductorwafer surface before the sample has been oxygen plasma ashed, whilepreventing or moderating the corrosion of the aluminum features.

EXAMPLE 19

Aqueous solution “H11” was prepared with 6.2 weight percenttetramethylammonium hydroxide (TMAH), 2.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 64 weightpercent glycerol and 2.9 weight percent (calculated as % SiO₂) colloidalsilica sol (with a particle size of 20 nm) added with the remainder ofthis solution being water. The pH of solution “H11” is about 13.1. Wafersamples #5 and #6 with one micron wide features and Aluminum-Copperraised lines capped with titanium-nitride, that had been previouslyprepared as follows: (a) metallization with aluminum-copper alloyfollowed by titanium nitride (b) lithographic patterning using aphotoresist material (c) pattern transfer using reactive ion etching (d)oxygen plasma ashing to remove organic photoresist residues, but leavingmainly inorganic residues behind were used. Treatments on each of thesamples were done for 5-10 minutes at 22-45° C., removed, rinsed withde-ionized water and dried with pressurized nitrogen gas. After drying,the sample was inspected on a Scanning Electron Microscope (SEM) todetermine the extent of cleaning and/or corrosion of the aluminum-coppermetal features. Results were similar to those obtained for solution “H7”in Example 17 and shows that colloidal silica can be used as a source ofwater-soluble metal ion-free silicate in the present invention.

EXAMPLE 20

Aqueous solution “L” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465, 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 3 weightpercent glycerol added with the remainder of this solution being waterand has a pH of about 12.1. Aqueous solution “Z” was prepared with 1.3weight percent tetramethylammonium hydroxide (TMAH), 0.58 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA) added(remainder of this solution being water) and has a pH of about 13.0.Aqueous solution “M1” was prepared with 1.2 weight percenttetramethylammonium hydroxide (TMAH), 0.45 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 18.5weight percent hydroxylamine and 0.07 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “P1” was prepared with 2.2 weightpercent tetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.6 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 11.5. Wafer sample #11 with 0.3-0.5 micronwide by 0.5 micron deep holes (vias) through dielectric and titaniumnitride layers exposing Aluminum-Copper metal at the base had beenpreviously processed as follows (a) metallization with aluminum-copperfollowed by titanium nitride (b) coated with silicon oxide dielectricusing chemical vapor deposition (c) lithographic patterning of viasusing a photoresist material (d) pattern transfer to the dielectriclayer using a reactive ion etching (e) oxygen plasma ashing to removemost of the residual photoresist. but leaving mainly inorganic titaniumcontaining residues behind (determined by Auger Electron Spectroscopicanalysis of cross-sectioned via residues). These samples were used toevaluate the performance of the solutions. A wafer sample was placed inthe solution at 22-65° C. for 20 minutes, removed, rinsed withde-ionized water and dried with pressurized nitrogen gas. After drying,the sample vias were cross-sectioned and then inspected on a FieldEmission Scanning Electron Microscope (FE-SEM) to determine the extentof cleaning and/or corrosion of the features. The results are shown inTable 19.

TABLE 19 FE-SEM Evaluation Results Weight Percent Tetramethyl- ammoniumTitanium Aluminum Silicate Time Residue Post-Ash Metal Added (min.)/Removal Residue Corrosion (calculated as Temp. Enhancer Removed (% MetalSolution % SiO₂) pH (° C.) Added (%) Loss) Z 0 13.0 20/22 NONE 0 100(severe) Z 0 13.0 20/65 NONE 98 100 (severe) L 0.14 12.1 20/45 NONE 1030 (moderate) L 0.14 12.1 20/65 NONE 20 50 (moderate) M1 0.14 12.1 20/35Hydroxylamine 100 3 (very slight) P1 0.14 11.5 20/35 Hydrogen 100 1(very slight) Peroxide

Referring to Table 19, the data shows the ability of hydroxylamine orhydrogen peroxide to enhance the removal of the titanium containingresidues at low temperatures.

EXAMPLE 21

Aqueous solution “M2” was prepared with 0.67 weight percenttetramethylammonium hydroxide (TMAH), 0.46 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 1.0weight percent hydroxylamine and 0.07 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “M3” was prepared with 0.94 weightpercent tetramethylammonium hydroxide (TMAH), 0.45 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.20 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 5.1weight percent hydroxylamine and 0.1 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “M4” was prepared with 1.1 weightpercent tetramethylammonium hydroxide (TMAH), 0.46 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.18 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 10.0weight percent hydroxylamine and 0.09 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “M5” was prepared with 1.3 weightpercent tetramethylammonium hydroxide (TMAH), 0.42 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylamrnonium silicate (TMAS) and47.3 weight percent hydroxylamine (remainder of this solution beingwater) and has a pH of about 12.1. Wafer sample #11 with 0.3-0.5 micronwide by 0.5 micron deep holes (vias) through dielectric and titaniumnitride layers exposing Aluminum-Copper metal at the base had beenpreviously processed as follows (a) metallization with aluminum-copperfollowed by titanium nitride (b) coated with silicon oxide dielectricusing chemical vapor deposition (c) lithographic patterning of viasusing a photoresist material (d) pattern transfer to the dielectriclayer using a reactive ion etching (e) oxygen plasma ashing to removemost of the residual photoresist, but leaving mainly inorganic titaniumcontaining residues behind (determined by Auger Electron Spectroscopicanalysis of cross-sectioned via residues). These samples were used toevaluate the performance of the solutions. A wafer sample was placed inthe solution at 35° C. for 20 minutes, removed, rinsed with de-ionizedwater and dried with pressurized nitrogen gas. After drying, the samplevias were cross-sectioned and then inspected on a Field EmissionScanning Electron Microscope (FE-SEM) to determine the extent ofcleaning and/or corrosion of the features. The results are shown inTable 20.

TABLE 20 FE-SEM Evaluation Results Weight Amount of Percent TitaniumTetramethyl- Residue ammonium Removal Aluminum Silicate Time EnhancerPost-Ash Metal Added (min.)/ Hydroxylamine Residue Corrosion (calculatedas Temp. Added Removed (% Metal Solution % SiO₂) pH (° C.) (Weight %)(%) Loss) M2 0.14 12.1 20/35 1.0 60 3 (slight) M3 0.20 12.1 20/35 5.1 961 (very slight) M4 0.18 12.1 20/35 10.0 99 3 (slight) M1 0.14 12.1 20/3518.5 100 3 (slight) M5 0.14 12.1 20/35 47.3 40 0

Referring to Table 20, the data shows the ability of hydroxylamine toenhance the removal of the titanium containing residues at lowtemperatures.

EXAMPLE 22

Aqueous solution “M6” was prepared with 0.82 weight percenttetramethylammonium hydroxide (TMAH), 0.14 weight percent (calculated as% SiO₂) tetramethylammonium silicate (TMAS), 18.8 weight percenthydroxylamine and 0.07 weight percent of the non-ionic surfactantSurfynol-465 (remainder of this solution being water) and has a pH ofabout 12.1. Wafer sample #11 with 0.3-0.5 micron wide by 0.5 micron deepholes (vias) through dielectric and titanium nitride layers exposingAluminum-Copper metal at the base had been previously processed asfollows (a) metallization with aluminum-copper followed by titaniumnitride (b) coated with silicon oxide dielectric using chemical vapordeposition (c) lithographic patterning of vias using a photoresistmaterial (d) pattern transfer to the dielectric layer using a reactiveion etching (e) oxygen plasma ashing to remove most of the residualphotoresist, but leaving mainly inorganic titanium containing residuesbehind (determined by Auger Electron Spectroscopic analysis ofcross-sectioned via residues). These samples were used to evaluate theperformance of the solutions. A wafer sample was placed in the solutionat 35° C. for 20 minutes. removed, rinsed with de-ionized water anddried with pressurized nitrogen gas. After drying, the sample vias werecross-sectioned and then inspected on a Field Emission Scanning ElectronMicroscope (FE-SEM) to determine the extent of cleaning and/or corrosionof the features. The results are shown in Table 21.

TABLE 21 FE-SEM Evaluation Results Weight Percent Amount of TitaniumTetramethyl- Metal Residue ammonium Chelating Removal Aluminum SilicateAgent Enhancer Post-Ash Metal Added CyDTA Hydroxylamine ResidueCorrosion (calculated as Added Added Removed (% Metal Solution % SiO₂)(Weight %) (Weight %) (%) Loss) M1 0.14 0.45 18.5 100 3 (slight) M6 0.140 18.8 100 4 (slight)

Referring to Table 21, the data shows that good stripping performancecan be obtained over a range of CyDTA concentrations. Thus, the amountof chelating agent present can be adjusted to accommodate the sample tobe cleaned. More difficult samples may require this optional ingredientto accomplish complete cleaning. The data also illustrate the optionaluse of a chelating agent in the compositions disclosed herein.

EXAMPLE 23

Aqueous solution “M7” was prepared with 6.0 weight percenttetramethylammonium hydroxide (TMAH), 0.35 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 1.2 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 17.7weight percent hydroxylamine and 0.06 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 13.0. Aqueous solution “M8” was prepared with 7.1 weightpercent tetramethylammonium hydroxide (TMAH), 0.46 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 2.7 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and19.1 weight percent hydroxyl amine (remainder of this solution beingwater) and has a pH of about 13.0. Aqueous solution “M9” was preparedwith 8.2 weight percent tetramethylammonium hydroxide (TMAH), 0.45weight percent trans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid(CyDTA), 4.1 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) and 19.0 weight percent hydroxylamine (remainder of thissolution being water) and has a pH of about 13.0. Wafer sample #11 with0.3-0.5 micron wide by 0.5 micron deep holes (vias) through dielectricand titanium nitride layers exposing Aluminum-Copper metal at the basehad been previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic titanium containing residues behind (determined by AugerElectron Spectroscopic analysis of cross-sectioned via residues). Thesesamples were used to evaluate the performance of the solutions. A wafersample was placed in the solution at 35° C. for 20 minutes. removed,rinsed with de-ionized water and dried with pressurized nitrogen gas.After drying, the sample vias were cross-sectioned and then inspected ona Field Emission Scanning Electron Microscope (FE-SEM) to determine theextent of cleaning and/or corrosion of the features. The results areshown in Table 22.

TABLE 22 FE-SEM Evaluation Results Weight Percent Titanium Tetramethyl-Residue ammonium Removal Aluminum Silicate Time Enhancer Post-Ash MetalAdded (min.)/ Hydroxylamine Residue Corrosion (calculated as Temp. AddedRemoved (% Metal Solution % SiO₂) pH (° C.) (Weight %) (%) Loss) M7 1.213.0 20/35 17.7 100 100 (severe) M8 2.7 13.0 20/35 19.1 100 80 (severe)M9 4.1 13.0 20/35 19.0 100 40 (moderate)

Referring to Table 22, the data shows the ability of tetramethylammoniumsilicate to prevent or moderate the corrosion of the exposed aluminum atthe base of the via even when the formulation pH is very high.

EXAMPLE 24

Aqueous solution “M10” was prepared with 0.34 weight percenttetramethylammonium hydroxide (TMAH), 0.47 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.01 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 18.6weight percent hydroxylamine and 0.06 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 10.1. Wafer sample #11 with 0.3-0.5 micron wide by 0.5micron deep holes (vias) through dielectric and titanium nitride layersexposing Aluminum-Copper metal at the base had been previously processedas follows (a) metallization with aluminum-copper followed by titaniumnitride (b) coated with silicon oxide dielectric using chemical vapordeposition (c) lithographic patterning of vias using a photoresistmaterial (d) pattern transfer to the dielectric layer using a reactiveion etching (e) oxygen plasma ashing to remove most of the residualphotoresist, but leaving mainly inorganic titanium containing residuesbehind (determined by Auger Electron Spectroscopic analysis ofcross-sectioned via residues). These samples were used to evaluate theperformance of the solutions. A wafer sample was placed in the solutionat 20-65° C. for 5-30 minutes, removed, rinsed with de-ionized water anddried with 20 pressurized nitrogen gas. After drying, the sample viaswere cross-sectioned and then inspected on a Field Emission ScanningElectron Microscope (FE-SEM) to determine the extent of cleaning and/orcorrosion of the features. The results are shown in Table 23.

TABLE 23 FE-SEM Evaluation Results Weight Percent Titanium Tetramethyl-Residue ammonium Removal Aluminum Silicate Time Enhancer Post-Ash MetalAdded (min.)/ Hydroxylamine Residue Corrosion (calculated as Temp. AddedRemoved (% Metal Solution % SiO₂) pH (° C.) (Weight %) (%) Loss) M100.01 10.1 20/35 18.6 5 0 M10 0.01 10.1 20/45 18.6 90 0 M10 0.01 10.120/55 18.6 100 2 (slight) M10 0.01 10.1 10/65 18.6 100 1 (very slight)M9 4.1 13.0  5/21 19.0 0 0 M9 4.1 13.0 20/20 19.0 99 2 (slight) M9 4.113.0 30/20 19.0 100 10 (light)

Referring to Table 23, the data shows at high pH, higher concentrationsof tetramethylammonium silicate can be used to inhibit aluminumcorrosion. The data also shows that at high pH, lower operatingtemperatures can be used.

EXAMPLE 25

Aqueous solution “P1” was prepared with 2.2 weight percenttetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.6 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 11.5. Aqueous solution “P2” was preparedwith 9.7 weight percent tetramethylammonium hydroxide (TMAH), 0.11weight percent trans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid(CyDTA), 0.14 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) and 9.4 weight percent hydrogen peroxide (remainder ofthis solution being water) and has a pH of about 11.5. Wafer sample #11with 0.3-0.5 micron wide by 0.5 micron deep holes (vias) throughdielectric and titanium nitride layers exposing Aluminum-Copper metal atthe base had been previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic titanium containing residues behind (determined by AugerElectron Spectroscopic analysis of cross-sectioned via residues). Thesesamples were used to evaluate the performance of the solutions. A wafersample was placed in the solution at 21-35° C. for 20 minutes, removed,rinsed with de-ionized water and dried with pressurized nitrogen gas.After drying, the sample vias were cross-sectioned and then inspected ona Field Emission Scanning Electron Microscope (FE-SEM) to determine theextent of cleaning and/or corrosion of the features. The results areshown in Table 24.

TABLE 24 FE-SEM Evaluation Results Weight Titanium Percent ResidueTetramethyl- Removal ammonium Enhancer Aluminum Silicate Time HydrogenPost-Ash Metal Added (min.)/ Peroxide Residue Corrosion (calculated asTemp. Added Removed (% Metal Solution % SiO₂) pH (° C.) (Weight %) (%)Loss) P1 0.14 11.5 20/22 1.6 99 0 P1 0.14 11.5 20/35 1.6 100 1 (veryslight) P2 0.14 11.5 20/21 9.4 99 0

Referring to Table 24, the data shows that a range of hydrogen peroxideconcentrations are useful for the removal of the titanium containingresidues in the vias.

EXAMPLE 26

Aqueous solution “P3” was prepared with 3.5 weight percenttetramethylammonium hydroxide (TMAH), 0.10 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.5 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 12.2. Aqueous solution “P4” was preparedwith 3.9 weight percent tetramethylammonium hydroxide (TMAH), 0.096weight percent trans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid(CyDTA), 0.59 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) and 1.4 weight percent hydrogen peroxide (remainder ofthis solution being water) and has a pH of about 12.2. Wafer sample #11with 0.3-0.5 micron wide by 0.5 micron deep holes (vias) throughdielectric and titanium nitride layers exposing Aluminum-Copper metal atthe base had been previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic titanium containing residues behind (determined by AugerElectron Spectroscopic analysis of cross-sectioned via residues). Thesesamples were used to evaluate the performance of the solutions. A wafersample was placed in the solution at 22° C. for 10 minutes, removed,rinsed with de-ionized water and dried with pressurized nitrogen gas.After drying, the sample vias were cross-sectioned and then inspected ona Field Emission Scanning Electron Microscope (FE-SEM) to determine theextent of cleaning and/or corrosion of the features. The results areshown in Table 25.

TABLE 25 FE-SEM Evaluation Results Weight Titanium Percent ResidueTetramethyl- Removal ammonium Enhancer Aluminum Silicate Time HydrogenPost-Ash Metal Added (min.)/ Peroxide Residue Corrosion (calculated asTemp. Added Removed (% Metal Solution % SiO₂) pH (° C.) (Weight %) (%)Loss) P1 0.14 11.5 10/22 1.6 99 0 P3 0.14 12.2 10/22 1.5 99 100 (severe)P4 0.59 12.2 10/22 1.4 99 6 (light)

Referring to Table 25, the data shows that higher concentrations oftetramethylammonium silicate can be used to inhibit aluminum corrosionwhen hydrogen peroxide is present.

EXAMPLE 27

Aqueous solution “P5” was prepared with 2.1 weight percenttetramethylammonium hydroxide (TMAH), 0.14 weight percent (calculated as% SiO₂) tetramethylammonium silicate (TMAS) and 1.5 weight percenthydrogen peroxide (remainder of this solution being water) and has a pHof about 11.5. Aqueous solution “P6” was prepared with 2.4 weightpercent tetramethylammonium hydroxide (TMAH), 0.53 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.6 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 11.5. Aqueous solution “P7” was preparedwith 2.9 weight percent tetramethylammonium hydroxide (TMAH), 1.4 weightpercent trans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA),0.14 weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) and 1.5 weight percent hydrogen peroxide (remainder of thissolution being water) and has a pH of about 11.5. Wafer sample #11 with0.3-0.5 micron wide by 0.5 micron deep holes (vias) through dielectricand titanium nitride layers exposing Aluminum-Copper metal at the basehad been previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic titanium containing residues behind (determined by AugerElectron Spectroscopic analysis of cross-sectioned via residues). Thesesamples were used to evaluate the performance of the solutions. A wafersample was placed in the solution at 21-23° C. for 20 minutes, removed,rinsed with de-ionized water and dried with pressurized nitrogen gas.After drying, the sample vias were cross-sectioned and then inspected ona Field Emission Scanning Electron Microscope (FE-SEM) to determine theextent of cleaning and/or corrosion of the features. The results areshown in Table 26.

TABLE 26 FE-SEM Evaluation Results Weight Titanium Percent Amount ofResidue Tetramethyl- Metal Removal ammonium Chelating Enhancer SilicateAgent Hydrogen Post-Ash Aluminum Added CyDTA Peroxide Residue Metal(calculated as Added Added Removed Corrosion Solution % SiO₂) (Weight %)(Weight %) (%) (% Metal Loss) P5 0.14 0 1.5 99 0 P1 0.14 0.11 1.6 99 0P6 0.14 0.53 1.6 97 0 P7 0.14 1.4 1.5 99 0

Referring to Table 26. the data shows that a range of CyDTAconcentrations are useful.

EXAMPLE 28

Aqueous solution “P8” was prepared with 0.40 weight percenttetramethylammonium hydroxide (TMAH), 0.10 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and19.2 weight percent hydrazine (remainder of this solution being water)and has a pH of about 12.1. Aqueous solution “P9” was prepared with 4.33weight percent tetramethylammonium hydroxide (TMAH), 0.088 weightpercent trans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA),0.12 weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) and 15.7 weight percent formaldehyde (remainder of this solutionbeing water) and has a pH of about 12.1. Aqueous solution “P10” wasprepared with 0.26 weight percent tetramethylammonium hydroxide (TMAH),11.5 weight percent trans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid(CyDTA), 0.13 weight percent (calculated as % SiO₂) tetramethylammoniumsilicate (TMAS) and 16.7 weight percent methylamine (remainder of thissolution being water) and has a pH of about 12.1. Wafer sample #11 with0.3-0.5 micron wide by 0.5 micron deep holes (vias) through dielectricand titanium nitride layers exposing Aluminum-Copper metal at the basehad been previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic titanium containing residues behind (determined by AugerElectron Spectroscopic analysis of cross-sectioned via residues). Thesesamples were used to evaluate the performance of the solutions. A wafersample was placed in the solution at 35° C. for 20-30 minutes, removed,rinsed with de-ionized water and dried with pressurized nitrogen gas.After drying, the sample vias were cross-sectioned and then inspected ona Field Emission Scanning Electron Microscope (FE-SEM) to determine theextent of cleaning and/or corrosion of the features. The results areshown in Table 27.

TABLE 27 FE-SEM Evaluation Results Weight Percent Tetramethyl- Potentialammonium Titanium Aluminum Silicate Time Residue Post-Ash Metal Added(min.)/ Removal Residue Corrosion (calculated as Temp. Enhancer Removed(% Metal Solution % SiO₂) pH (° C.) Added (%) Loss) P8 0.14 12.1 30/35hydrazine 0 0 P9 0.12 12.1 30/35 formaldehyde 5 50 (moderate) P10 0.1312.1 20/35 methylamine 0 0

Referring to Table 27, the data shows that other small molecules wereineffective for titanium residue removal. Like hydroxylamine, hydrazineis a powerful reducing agent. Hydrazine's lack of effectiveness wasunexpected and demonstrates the uniqueness of hydroxylamine and hydrogenperoxide for enabling the titanium containing residues found in wafersample #11 to be cleaned from the vias using silicate-containingformulations.

EXAMPLE 29

Aqueous solution “L” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465, 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 3 weightpercent glycerol added with the remainder of this solution being waterand has a pH of about 12.1. Aqueous solution “M1” was prepared with 1.2weight percent tetramethylammonium hydroxide (TMAH), 0.45 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 18.5weight percent hydroxylamine and 0.07 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “P8” was prepared with 0.40 weightpercent tetramethylammonium hydroxide (TMAH), 0.10 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and19.2 weight percent hydrazine (remainder of this solution being water)and has a pH of about 12.1. Aqueous solution “S1” was prepared bycombining 583 grams de-ionized water, 7.8 grams 25% aqueoustetramethylammonium hydroxide (TMAH) and 8.6 grams tetramethylammoniumsilicate (TMAS, 10.0% as SiO₂) and had a pH of 12.5. Aqueous solution“S2” was prepared by combining 99.0 grams of solution “S1” and 2.5 gramsof β-Cyclodextrin (solution pH=12.1). Aqueous solution “S3” was preparedby combining 99.0 grams of solution “S1” and 2.5 grams of SodiumHypophosphite (solution pH=12.3). Aqueous solution “S4” was prepared bycombining 99.0 grams of solution “S1” and 2.5 grams of Sodium Dithionite(solution pH=6.7). Aqueous solution “S5” was prepared by combining 99.0grams of solution “S1” and 2.5 grams of Sodium Sulfite (solutionpH=12.3). Aqueous stock solution “S5b” was prepared by combining 1,775.2grams de-ionized water, 96.0 grams 25% aqueous tetramethylammoniumhydroxide (TMAH), 8.8 gramstrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA) and 114.8grams tetramethylammonium silicate (TMAS, 10.0% as SiO₂). Aqueous stocksolution “S5c” was prepared by combining 900 ml de-ionized water and 300ml solution “S5b”. Aqueous solution “S6” was prepared by combining 80.0grams solution “S5c”, 5.0 grams L-ascorbic acid and 18.2 grams 25%aqueous tetramethylammonium hydroxide (TMAH) (solution pH=12.3). Aqueoussolution “S7” was prepared by combining 80.0 grams solution “S5c”, 5.0grams hydroquinone and 27.1 grams 25% aqueous tetramethylammoniumhydroxide (TMAH) (solution pH=12.4). Aqueous solution “S8” was preparedby combining 80.0 grams solution “S5c”, 5.0 grams L-(+)-cysteine and29.6 grams 25% aqueous tetramethylammonium hydroxide (TMAH) (solutionpH=12.4). Aqueous solution “S9” was prepared by combining 80.0 gramssolution “S5c”, 10.0 grams Ammonium Persulfate and 32.9 grams 25%aqueous tetramethylammonium hydroxide (TMAH) (solution pH=12.6). Aqueoussolution “S10” was prepared by combining 80.0 grams solution “S5c”, 5.0grams Nitric Acid and 10.2 grams tetramethylammonium hydroxidepentahydrate (TMAH) (solution pH=12.4). Aqueous solution “S11” wasprepared by combining 90.0 grams solution “S5c”, 5.0 grams and 19.2grams 25% aqueous tetramethylammonium hydroxide (TMAH) (solutionpH=12.3). Aqueous solution “S 12” was prepared by combining 80.0 gramssolution “S5c”, 5.0 grams 88% Formic Acid, 10.0 grams 25% aqueoustetramethylammonium hydroxide (TMAH) and 12.7 grams tetramethylammoniumhydroxide pentahydrate (TMAH) (solution pH=12.6). Aqueous solution “S13”was prepared by combining 80.0 grams solution “S5c”, 5.0 grams SulfuricAcid and 17.5 grams tetramethylammonium hydroxide pentahydrate (TMAH)(solution pH=12.3). Aqueous solution “S14” was prepared by combining80.0 grams solution “S5c”, 5.0 grams Phosphoric Acid and 20.1 gramstetramethylammonium hydroxide pentahydrate (TMAH) (solution pH=12.3).Aqueous solution “S15” was prepared by combining 80.0 grams solution“S5c”, 6.0 grams Oxalic Acid Dihydrate. 16.0 grams 25% aqueoustetramethylammonium hydroxide (TMAH) and 9.3 grams tetramethylammoniumhydroxide pentahydrate (TMAH) (solution pH=12.6). Aqueous solution “S16”was prepared by combining 80.0 grams solution “S5c”, 5.0 grams Catecholand 16.1 grams 25% aqueous tetramethylammonium hydroxide (TMAH)(solution pH=12.4). Each solution was placed into a 125 ml polyethylenebottle, tightly capped and placed into a oven set at 45° C. for 1 hourof pre-heating. A 0.025 mm×13 mm×50 mm, 99.94% pure titanium foil couponwas washed with de-ionized water, acetone, dried, then weighed on ananalytical balance. After one hour of pre-heating each solution wasremoved from the oven and the titanium foil coupon was then placed intothe bottle. tightly re-capped and placed back into the oven. After 24hours at about 45° C., the bottle was removed from the oven. Thetitanium foil coupon was removed, rinsed with de-ionized water, followedby an acetone rinse, dried and then weighed on an analytical balance.The relative corrosion rates were determined by weight loss. The resultsare shown in Table 28.

TABLE 28 Titanium Foil Etch Rate Comparisons Relative Titanium CorrosionPotential Titanium Residue Rate Solution pH Removal Enhancer Added (allrelative to Solution L) L 12.1 NONE 1 A 12.2 NONE 1.3 P8 12.1 hydrazine0 S1 12.5 NONE 1.7 S2 12.2 β-Cyclodextrin 0.7 S3 6.7 SodiumHypophosphite 0.7 S4 12.3 Sodium Dithionite 1.7 S5 12.3 Sodium Sulfite1.7 S6 12.3 Ascorbic Acid 0 S7 12.3 Hydroquinone 0 S8 12.4 Cysteine 0 S912.2 Ammonium Persulfate 0.3 S10 12.4 Nitric Acid 0.3 S11 12.3 Phenol 0S12 12.7 Formic Acid 0 S13 12.1 Sulfuric Acid 0 S14 12.3 Phosphoric Acid0 S15 12.6 Oxalic Acid 0 S16 12.5 Catechol 0 M1 12.1 Hydroxylamine 67

Referring to Table 28, the data shows that at the low processtemperature of 45° C., all of the above tested potential titaniumresidue removal enhancers (with the exception of hydroxylamine) wereineffective. The lack of effectiveness for hydrazine shown here confirmsthe FE-SEM results shown in Example 28. The results shown demonstratethe uniqueness of hydroxylamine for enhancing the relative titanium etch(removal) rates.

EXAMPLE 30

Aqueous solution “R1” was prepared by combining 583 grams de-ionizedwater, 4.68 grams 25% aqueous tetramethylammonium hydroxide (TMAH) and8.64 grams tetramethylammonium silicate (TMAS, 10.0% as SiO₂) and 0.66grams trans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA) and hada pH of 11.3. Aqueous solution “R2” was prepared by combining 99.0 gramsof solution “R1”, 0.33 grams of 25% aqueous tetramethylammoniumhydroxide (TMAH) and 1.0 grams of 50% aqueous hydroxylamine (solutionpH=12.0). Aqueous solution “R3” was prepared by combining 99.0 grams ofsolution “R1”, 0.34 grams of 25% aqueous tetramethylammonium hydroxide(TMAH) and 5.0 grams of 50% aqueous hydroxylamine (solution pH=l 1.9).Aqueous solution “R4” was prepared by combining 99.0 grams of solution“R1”, 0.34 grams of 25% aqueous tetramethylammonium hvdroxide (TMAH) and10.0 grams of 50% aqueous hydroxylamine (solution pH=11.6). Aqueoussolution “R5” was prepared by combining 99.0 grams of solution “R1”,0.52 grams of 25% aqueous tetramethylammonium hydroxide (TMAH) and 1.0grams of 50% aqueous hydroxylamine (solution pH=12.2). Aqueous solution“R6” was prepared by combining 99.0 grams of solution “R1”, 0.54 gramsof 25% aqueous tetramethylammonium hydroxide (TMAH) and 5.0 grams of 50%aqueous hydroxylamine (solution pH=12.0). Aqueous solution “R7” wasprepared by combining 99.0 grams of solution “R1”, 0.56 grams of 25%aqueous tetramethylammonium hydroxide (TMAH) and 10.2 grams of 50%aqueous hydroxylamine (solution pH=11.8). Aqueous stock solution “R8”was prepared by combining 583 grams de-ionized water, 4.68 grams 25%aqueous tetramethylammonium hydroxide (TMAH) and 8.64 gramstetramethylammonium silicate (TMAS, 10.0% as SiO₂) and had a pH of 12.0.Aqueous solution “R9” was prepared by combining 94.0 grams of solution“R8” and 20.0 grams of 50% aqueous hydroxylamine (solution pH=11.3).Each solution was placed into a 125 ml polyethylene bottle, tightlycapped and placed into a oven set at 45° C. for 1 hour of pre-heating. A0.025 mm×13 mm×50 mm, 99.94% pure titanium foil coupon was washed withde-ionized water, acetone, dried, then weighed on an analytical balance.After one hour of pre-heating each solution was removed from the ovenand the titanium foil coupon was then placed into the bottle, tightlyre-capped and placed back into the oven. After 24 hours at about 45° C.,the bottle was removed from the oven. The titanium foil coupon wasremoved, rinsed with de-ionized water, followed by an acetone rinse,dried and then weighed on an analytical balance. The relative corrosionrates were determined by weight loss. The results are shown in Table 29.

TABLE 29 Titanium Foil Etch Rate Comparisons Amount Titanium ResidueRemoval Enhancer Relative Hydroxylamine in Titanium FormulationCorrosion Solution pH (Weight %) Rate R2 12.0 0.50 1 R5 12.2 0.51 1.7 R311.9 2.4 5.6 R6 12.0 2.4 5.8 R4 11.6 4.6 20 R7 11.8 4.7 23 R9 11.3 8.931

Referring to Table 29, the data shows that as the concentration of thetitanium residue removal enhancer hydroxylamine is increased, therelative titanium foil removal rate also increases. The titanium removalrate in this test is proportional to effectiveness in cleaning wafersample #11.

EXAMPLE 31

Aqueous solution “M1” was prepared with 1.2 weight percenttetramethylammonium hydroxide (TMAH), 0.45 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 18.5weight percent hydroxylamine and 0.07 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “P1” was prepared with 2.2 weightpercent tetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.6 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 11.5. Commercially available post etchresidue removers used for comparisons were EKC-265™ (a product of EKCTechnology, Inc.) and ACT-935TM (a product of ACT, Inc.). Wafer sample#11 with 0.3-0.5 micron wide by 0.5 micron deep holes (vias) throughdielectric and titanium nitride layers exposing Aluminum-Copper metal atthe base had been previously processed as follows (a) metallization withaluminum-copper followed by titanium nitride (b) coated with siliconoxide dielectric using chemical vapor deposition (c) lithographicpatterning of vias using a photoresist material (d) pattern transfer tothe dielectric layer using a reactive ion etching (e) oxygen plasmaashing to remove most of the residual photoresist, but leaving mainlyinorganic titanium containing residues behind (determined by AugerElectron Spectroscopic analysis of cross-sectioned via residues). Thesesamples were used to evaluate the performance of the solutions. A wafersample was placed in the solution at 35° C. for 20 minutes. removed,rinsed with de-ionized water and dried with pressurized nitrogen gas.After drying. the sample vias were cross-sectioned and then inspected ona Field Emission Scanning Electron Microscope (FE-SEM) to determine theextent of cleaning and/or corrosion of the features. The results areshown in Table 30.

TABLE 30 FE-SEM Evaluation Results Comparison Titanium Residue Post-AshAluminum Removal Residue Metal Time Temp. Enhancer Removed CorrosionSolution pH (min.) (° C.) Added (%) (% Metal Loss) P1 11.5 20 35Hydrogen 100 1 (very slight) Peroxide M1 12.1 20 35 Hydroxylamine 100 3(slight) EKC-265 ™ 11.5- 20 35 Contains 0 0 12.0 Hydroxylamine (fromMSDS) ACT-935 ™ 11.0 20 35 Contains 0 0 (from Hydroxylamine MSDS)

Referring to Table 30, the data shows that at the low processtemperature of 35° C., the compositions of this invention were effectivein removing residues known to contain titanium. This data also showsthat the use of the titanium residue removal enhancer hydroxylamine forlow temperature cleaning is unique to the compositions of thisinvention.

EXAMPLE 32

Aqueous solution “L” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465, 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 3 weightpercent glycerol added with the remainder of this solution being waterand has a pH of about 12.1. Aqueous solution “M1” was prepared with 1.2weight percent tetramethylammonium hydroxide (TMAH), 0.45 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 18.5weight percent hydroxylamine and 0.07 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “P1” was prepared with 2.2 weightpercent tetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.6 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 11.5. A silicon wafer sample with a curedlayer of hydrogen silsesquioxane (HSQ) low-k dielectric was placed in aFourier Transform Infra-Red (FTIR) Spectrometer and a reference spectrawas taken. HSQ has Si-H bonds in its structure and is apparent at 2100cm⁻¹. The wafer sample was then treated in one of the above solutionsfor 10 minutes at room temperature (about 22° C.), rinsed withde-ionized water, then dried. The sample was then placed into the FTIRand a second spectrum obtained. The S-H peak area at about 2100 cm⁻¹ wasused for comparing the treated wafer spectrum to the reference spectrum.A commercially available post etch residue remover, EKC-265™ (a productof EKC Technology, Inc.) was also tested in the same manner, at themanufacturer's recommended temperature of 65° C. (10 minutes), forcomparison. The results are shown in Table 31.

TABLE 31 HSQ Low-k Dielectric Compatibility Test Results PercentTitanium Si-H Residue Infra-Red Removal Peak Time Temp. EnhancerRemaining Solution pH (min.) (° C.) Added in HSQ L 12.1 10 22 NONE 95 P111.5 10 22 Hydrogen 99.5 Peroxide M1 12.1 10 22 Hydroxylamine 85EKC-265 ™ 11.5-12.0 10 65 Contains 0 (from Hydroxylamine MSDS)

Referring to Table 31, the data shows that the compositions of thisinvention are unique in that they are compatible with sensitive low-kdielectric substrates such as HSQ.

EXAMPLE 33

Aqueous solution “A” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465 (a product of AirProducts and Chemicals, Inc.) and 0.14 weight percent (calculated as %SiO₂) tetramethylammonium silicate (TMAS) added (remainder of thissolution being water) and has a pH of about 12.2. Aqueous solution “L”was prepared with 0.3 weight percent tetramethylammonium hydroxide(TMAH), 0.1 weight percent trans-(1,2-cyclohexylenedinitrilo)tetraaceticacid (CyDTA), 0.07 weight percent of the non-ionic surfactantSurfynol-465. 0.14 weight percent (calculated as % SiO₂)tetramethylammonium silicate (TMAS) and 3 weight percent glycerol addedwith the remainder of this solution being water and has a pH of about12.1. Aqueous solution “M1” was prepared with 1.2 weight percenttetramethylammonium hydroxide (TMAH), 0.45 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 18.5weight percent hydroxylamine and 0.07 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “P1” was prepared with 2.2 weightpercent tetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.6 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 11.5. Aqueous stock solution “T1” wasprepared with 1.6 weight percent tetramethylammonium hydroxide (TMAH),0.41 weight percent trans-(1,2-cyclohexylenedinitrilo)tetraacetic acid(CyDTA), 0.27 weight percent of the non-ionic surfactant Surfynol-465,0.56 weight percent (calculated as % SiO₂) tetramethylammonium silicate(TMAS) and 12 weight percent glycerol added with the remainder of thissolution being water and has a pH of about 12.5. Aqueous solution “T2”was prepared by diluting 25 ml solution “T1” with 70 ml de-ionized waterand 5 ml of glycerol. Aqueous solution “T3” was prepared by diluting 25ml solution “T1” with 65 ml de-ionized water and 10 ml of glycerol.Aqueous solution “T4” was prepared by diluting 25 ml solution “T1” with60 ml de-ionized water and 15 ml of glycerol. Aqueous solution “T5” wasprepared by diluting 25 ml solution “T1” with 55 ml de-ionized water and20 ml of glycerol. Aqueous solution “T6” was prepared by diluting 25 mlsolution “T1” with 50 ml de-ionized water and 25 ml of glycerol. Aqueoussolution “T7” was prepared by diluting 25 ml solution “T1” with 25 mlde-ionized water and 50 ml of glycerol. Aqueous solution “T8” wasprepared by diluting 25 ml solution “T1” with 75 ml of glycerol. Aqueoussolution “T9” was prepared by diluting 25 ml solution “T1” with 70 mlde-ionized water and 5 ml of 1-(2-hydroxyethyl)-2-pyrrolidinone (HEP).Aqueous solution “T10” was prepared by diluting 25 ml solution “T1” with65 ml de-ionized water and 10 ml of 1-(2-hydroxyethyl)-2-pyrrolidinone(HEP). Aqueous solution “T11” was prepared by diluting 25 ml solution“T1” with 60 ml de-ionized water and 15 ml of1-(2-hydroxyethyl)-2-pyrrolidinone (HEP). Aqueous solution “T12” wasprepared by diluting 25 ml solution “T1” with 55 ml de-ionized water and20 ml of 1-(2-hydroxyethyl)-2-pyrrolidinone (HEP). Aqueous solution“T13” was prepared by diluting 25 ml solution “T1” with 50 ml de-ionizedwater and 25 ml of 1-(2-hydroxyethyl)-2-pyrrolidinone (HEP). Aqueoussolution “T14” was prepared by diluting 25 ml solution “T1” with 25 mlde-ionized water and 50 ml of 1-(2-hydroxyethyl)-2-pyrrolidinone (HEP).Aqueous solution “T15” was prepared by diluting 25 ml solution “T1” with75 ml of 1-(2-hydroxyethyl)-2-pyrrolidinone (HEP). Each solution wasplaced into a 125 ml polyethylene bottle, tightly capped and eitherplaced into a oven set at 45° C., 65° C. or 85° C. for 1 hour ofpre-heating or kept at room temperature (about 22° C.). A 0.025 mm×13mm×50 mm, pure copper foil coupon was dipped in dilute hydrochloricacid, washed with de-ionized water, acetone, dried, then weighed on ananalytical balance. After one hour of pre-heating each solution wasremoved from the oven (if heated) and the copper foil coupon was thenplaced into the bottle, tightly re-capped and placed back into the oven.After 24 hours at about 22-85° C., the bottle was removed from the oven.The copper foil coupon was removed, rinsed with de-ionized water,followed by an acetone rinse, dried and then weighed on an analyticalbalance. The corrosion rates were determined by weight loss.Commercially available post etch residue removers EKC-265™ (a product ofEKC Technology, Inc.), EKC-270™ (a product of EKC Technology, Inc.),EKC-311™ (a product of EKC Technology, Inc.), ACT-935TM (a product ofACT, Inc.), ACT NP-937™ (a product of ACT, Inc.) and ACT-941™ (a productof ACT, Inc.) was also tested in the same manner, at the manufacturer'srecommended temperature of 65° C., for comparison. The results are shownin Table 32.

TABLE 32 Copper Foil Etch Rate Comparisons Titanium Organic Co- CopperFoil Residue Solvent(s) Added Tem- Corrosion Removal to Reduce Copperper- Rate Enhancer Corrosion ature (Angstroms/ Solution Added (Volume %)(° C.) hour) P1 Hydrogen NONE RT 0 Peroxide 45 29 A NONE NONE 45 170 LNONE Glycerol (2.4%) RT 38 45 190 85 135 T2 NONE Glycerol (7.4%) 85 79T3 NONE Glycerol (12.4%) 85 46 T4 NONE Glycerol (17.4%) 85 30 T5 NONEGlycerol (22.4%) 85 7 T6 NONE Glycerol (27.4%) 85 0 T7 NONE Glycerol(52.4%) 85 0 T8 NONE Glycerol (77.4%) 85 8 T9 NONE Glycerol (2.4%) 85 26HEP (5.0%) T10 NONE Glycerol (2.4%) 85 24 HEP (10%) T11 NONE Glycerol(2.4%) 85 19 HEP (15%) T12 NONE Glycerol (2.4%) 85 0 HEP (20%) T13 NONEGlycerol (2.4%) 85 7 HEP (25%) T14 NONE Glycerol (2.4%) 85 11 HEP (50%)T15 NONE Glycerol (2.4%) 85 11 HEP (75%) ACT-935 ™ Contains Unknown65 >125,000 Hydroxylamine ACT NP- Contains Unknown 65 66,900 937 ™Hydroxylamine ACT-941 ™ Contains Unknown 65 >125,000 HydroxylamineEKC-265 ™ Contains Unknown 65 >125,000 Hydroxylamine EKC-270 ™ ContainsUnknown 65 >62,000 Hydroxylamine EKC-311 ™ Contains Unknown 65 >62,000Hydroxylamine M1 Hydroxylamine NONE 45 3,600* *16 hour test at 45° C.

Referring to Table 32, the data shows that several of the compositionsof this invention are compatible with copper. The data also shows thatM1, a composition of this invention is superior to commerciallyavailable hydroxylamine-containing post etch residue removerformulations for use with copper metallizations. Additionally, the datashows that the addition of the titanium residue removal enhancerhydrogen peroxide reduces the copper corrosion rate.

EXAMPLE 34

Aqueous solution “L” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465, 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 3 weightpercent glycerol added with the remainder of this solution being waterand has a pH of about 12.1. In a clean-room, a wafer particle counterwas used to count the total particles (0.1-10 microns is size) found ona 3 inch silicon wafer with 650 angstroms of thermal oxide. The waferwas then chemically mechanically polished (CMP) with an alumina-basedpolishing slurry then rinsed with de-ionized water. Solution “L” wasthen used at room temperature (about 22° C.) to “brush-clean” the wafer,followed by rinsing with de-ionized water and spin drying. The waferparticle counter was then used to count the total particles present(0.1-10 microns in size) on the wafer's surface after cleaning. Forcomparison, a second wafer was tested with de-ionized water used as thepost-CMP “brush-cleaner”. The results are shown in Table 33.

TABLE 33 Post-CMP Cleaning Test Results Total Particle Total ParticleCounts After Time Temp. Counts Before Post-CMP Solution pH (min.) (° C.)CMP Cleaning DI-Water 7 10 22 672 29,484 L 12.1 10 22 782 103

Referring to Table 33, the data shows that the compositions of thisinvention are unique because they remove particulate contaminationoccurring after chemical mechanical polishing.

EXAMPLE 35

Aqueous solution “L” was prepared with 0.3 weight percenttetramethylammonium hydroxide (TMAH), 0.1 weight percenttrans-(1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), 0.07 weightpercent of the non-ionic surfactant Surfynol-465, 0.14 weight percent(calculated as % SiO₂) tetramethylammonium silicate (TMAS) and 3 weightpercent glycerol added with the remainder of this solution being waterand has a pH of about 12.1. Aqueous solution “M1” was prepared with 1.2weight percent tetramethylammonium hydroxide (TMAH), 0.45 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS), 18.5weight percent hydroxylamine and 0.07 weight percent of the non-ionicsurfactant Surfynol-465 (remainder of this solution being water) and hasa pH of about 12.1. Aqueous solution “P1” was prepared with 2.2 weightpercent tetramethylammonium hydroxide (TMAH), 0.11 weight percenttrans-(1,2-cyclohexylenedinitrilo)-tetraacetic acid (CyDTA), 0.14 weightpercent (calculated as % SiO₂) tetramethylammonium silicate (TMAS) and1.6 weight percent hydrogen peroxide (remainder of this solution beingwater) and has a pH of about 11.5. Sections from the same Si(100) waferwith approximately 650 nm of thermal oxide were washed with acetone,dried, then measured with a Rudolph FTM Interferometer to determine thethermal oxide thickness. Four areas were measured and mapped for afollow-up measurement after treatment. Each sample was then placed intothe bottle, loosely re-capped and placed into the oven, which waspre-set to 45° C. or left at room temperature (about 22° C.). After 24hours at about 22° C. or about 45° C., the bottle was removed from theoven, sample removed, rinsed with water, followed by an acetone rinse,dried and then measured on the Interferometer. The relative etch rateswere determined by the difference in thermal oxide film thicknessaveraged for four areas on the sample. Commercially available post etchresidue removers EKC-265™ (a product of EKC Technology, Inc.), EKC-270™(a product of EKC Technology, Inc.), EKC-311™ (a product of EKCTechnology, Inc.), ACT-935™ (a product of ACT, Inc.), ACT NP-937™ (aproduct of ACT, Inc.) and ACT-941™ (a product of ACT, Inc.) was alsotested in the same manner, at the manufacturer's recommended temperatureof 65° C., for comparison. The results are shown in Table 34.

TABLE 34 Thermal Oxide on Silicon Etch Rate Comparisons Titanium ThermalResidue Oxide Removal Etch Rate Temp. Enhancer (Angstroms/ Solution pH(° C.) Added hour) L 12.1 45 NONE 4.2 P1 11.5 22 Hydrogen 1.2 PeroxideM1 12.1 45 Hydroxylamine 0 ACT-935 ™ 11.0 65 Contains 6* (from MSDS)Hydroxylamine ACT NP- 11.1 65 Contains 6* 937 ™ (from MSDS)Hydroxylamine ACT-941 ™ 11.5 65 Contains 6* (from MSDS) HydroxylamineEKC-265 ™ 11.5-12.0 65 Contains 7.2 (from MSDS) Hydroxylamine EKC-270 ™10.8 65 Contains 13.7 Hydroxylamine EKC-311 ™ 10.8-11.4 65 Contains 12.6(from MSDS) Hydroxylamine *18 hour test at 65° C.

Referring to Table 34, the data shows that the compositions of thisinvention are unique in that they clean unwanted residues from wafersubstrates without unwanted etching of the dielectric layer. Theseresults agree with the results presented in Example #15 for silicatecontaining compositions. The examples illustrate ten surprising andunexpected results associated with this invention. First, the ability toclean unwanted residues from wafer surfaces at low operatingtemperatures and times while preventing unwanted metal corrosion.Second, the unexpectedly high bath stability of very dilute, high pHcompositions using silicate (pKa=11.8) as a buffer. Third, silicatesadded to the highly alkaline cleaners inhibit the unwanted dissolutionof silicon dioxide dielectric materials present in integrated circuits.Fourth, since the compositions are highly aqueous (typically >80%water), no intermediate rinse is needed before the water rinse toprevent post-cleaning corrosion. Fifth, because of the high watercontent of these compositions, the health, safety and environmentalrisks associated with use and handling are significantly reduced overtypical organic photoresist strippers and post plasma ash residueremovers. Sixth, the compositions of this invention have been shown toleave substantially less carbon residual contamination on the substratesurface after treatment when compared to a typical organic post-ashresidue remover. Seventh, the compositions of this invention have beenfound to be compatible with the sensitive low-k dielectric materialsused in integrated circuits. Eighth, the ability to remove difficulttitanium containing residues at low temperatures. Ninth, thecompositions of this invention have been found to be compatible withcopper metal. Tenth, the compositions of this invention have also beenfound to be effective in removing silica and alumina chemical mechanicalpolishing (CMP) slurry residues from wafer substrates. While silicatesare known aluminum corrosion inhibitors, the ability to inhibit aluminumcorrosion, yet selectively remove metal-containing photoresist residues,that typically have a high aluminum and/or titanium content, wassurprising and unexpected. The buffering action of silicate, thenegligible carbon contamination of the substrate surface duringtreatment, the low dielectric etching rate. compatibility with sensitivelow-k dielectric materials, compatibility with copper metal, ability toremove difficult titanium containing residues at low temperatures,ability to clean silica and alumina chemical mechanical polishing (CMP)slurry residues and the ability to effectively employ such high waterconcentrations were also surprising and unexpected aspects of thisinvention.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

I claim:
 1. A composition for stripping or cleaning integrated circuitsubstrates, comprising: (a) one or more metal ion-free bases; (b) awater-soluble metal ion-free silicate; (c) one or more chelating agents;and (d) water, wherein the chelating agent is selected from the groupconsisting of (ethylenedinitrilo)tetraacetic acid,diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid,1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid,N,N,N′,N′-ethylenediaminetetra(methylenephosphonic acid), and(1,2-cyclohexyllenedinitrilo)-tetraacetic acid.
 2. The composition ofclaim 1 wherein the metal ion-free bases are present in sufficientamounts to produce a pH of from about 11 to about
 13. 3. The compositionof claim 1 wherein the concentration of water-soluble metal ion-freesilicate is from about 0.01% to about 5% by weight (as SiO₂) of thecomposition.
 4. The composition of claim 1, wherein the concentration ofchelating agents is from about 0.01% to about 10% by weight of thecomposition.
 5. The composition of claim 1 further containing one ormore water-soluble organic co-solvents.
 6. The composition of claim 5wherein the concentration of water-soluble organic co-solvents is fromabout 0.1% to about 80% by weight of the composition.
 7. The compositionof claim 5 wherein said water-soluble organic co-solvent is selectedfrom the group consisting of 1-hydroxyalkyl-2-pyrrolidinones, alcoholsand polyhydroxy compounds.
 8. The composition of claim 1 furthercontaining one or more titanium residue removal enhancing agents.
 9. Thecomposition of claim 8 wherein the concentration of titanium residueremoval enhancing agents is from about 1% to about 50% by weight of thecomposition.
 10. The composition of claim 1 wherein the titanium residueremoval enhancing agent is selected from the group consisting ofhydroxylamine, hydroxylamine salts, peroxides, ozone and fluoride. 11.The composition of claim 1 further containing one or more water-solublesurfactants.
 12. The composition of claim 11 wherein the concentrationof water-soluble surfactants is from about 0.01% to about 1% by weightof the composition.
 13. The composition of claim 1 wherein the base isselected from the group consisting of hydroxides and organic amines. 14.The composition of claim 13 wherein the base is selected from the groupconsisting of quaternary ammonium hydroxides, ammonium hydroxides, andorganic amines.
 15. The composition of claim 1 wherein the base isselected from the group consisting of choline, tetrabutylammoniumhydroxide, tetramethylammonium hydroxide, methyltriethanolammoniumhydroxide, and methyltriethylammonium hydroxide.
 16. The composition ofclaim 1 wherein the water-soluble metal ion-free silicate is selectedfrom the group consisting of ammonium silicates and quaternary ammoniumsilicates.
 17. The composition of claim 1 wherein the water-solublemetal ion-free silicate is tetramethylammonium silicate.
 18. Thecomposition of claim 1 containing from about 0.1-3% by weight of thecomposition of tetramethylammonium hydroxide and about 0.01-1% by weightof the composition of tetramethylammonium silicate.
 19. The compositionof claim 18 further containing from about 0.01-1% by weight of thecomposition of trans-(1,2-cyclohexylenedinitrilo)tetraacetic acid. 20.The chemical composition formed by mixing (a) one or more metal ion-freebases; (b) a water-soluble metal ion-free silicate; (c) one or morechelating agents; and (d) water, wherein the chelating agent is selectedfrom the group consisting of (ethylenedinitrilo)tetraacetic acid,diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid,1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid,N,N,N′,N′-ethylenediaminetetra(methylenephosphonic acid), and(1,2-cyclohexyllenedinitrilo)-tetraacetic acid.
 21. A composition forstripping or cleaning integrated circuit substrates, comprising: (a) oneor more metal ion-free bases; (b) a water-soluble metal ion-freesilicate; (c) one or more titanium residue removal enhancing agents; and(d) water.
 22. The composition of claim 21 wherein the concentration oftitanium residue removal enhancing agent is from about 1% to about 50%by weight of the composition.
 23. The composition of claim 22 whereinthe titanium residue removal enhancing agent is selected from the groupconsisting of hydroxylamine, hydroxylamine salts, peroxides, ozone andfluoride.
 24. The composition of claim 23 wherein the one or moremetal-ion free bases are present in an amount sufficient to produce a pHof the composition of from about 11 to about 13.1
 25. The composition ofclaim 23 wherein the concentration of water-soluble metal ion-freesilicate is from about 0.01% to about 5% by weight (as SiO₂) of thecomposition.
 26. The composition of claim 23 further containing one ormore chelating agents.
 27. The composition of claim 26 wherein theconcentration of chelating agents is from about 0.01% to about 10% byweight of the composition.
 28. The composition of claim 27 wherein thechelating agent is an aminocarboxylic acid.
 29. The composition of claim27 wherein the chelating agent is selected from the group consisting of(ethylenedinitrilo)tetraacetic acid, diethylenetriamine-pentaaceticacid, triethylenetetraminehexaacetic acid,1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid,N,N,N′,N′-ethylenediaminetetra-(methylenephosphonic acid), and(1,2-cyclohexyllenedinitrilo)-tetraacetic acid.
 30. The composition ofclaim 23 further containing one or more water-soluble organicco-solvents.
 31. The composition of claim 30 wherein the concentrationof water-soluble organic co-solvents is from about 0.1% to about 80% byweight of the composition.
 32. The composition of claim 30 wherein saidwater-soluble organic co-solvent is selected from the group consistingof 1-hydroxyalkyl-2-pyrrolidinones, alcohols and polyhydroxy compounds.33. The composition of claim 23 further containing one or morewater-soluble surfactants.
 34. The composition of claim 33 wherein thewater-soluble surfactant is a nonionic ethoxylated acetylenic diolsurfactant.
 35. The composition of claim 23 wherein the metal ion-freebase is selected from the group consisting of hydroxides and organicamines.
 36. The composition of claim 35 wherein the metal ion-free baseis selected from the group consisting of quaternary ammonium hydroxides,ammonium hydroxides and organic amines.
 37. The composition of claim 23wherein the metal ion-free base is selected from the group consisting ofcholine, tetrabutylammonium hydroxide, tetramethyammmonium hydroxide,methyltriethanolammonium hydroxide, and methyltriethylammoniumhydroxide.
 38. The composition of claim 23 wherein the water-solublemetal ion-free silicate is selected from the group consisting ofammonium silicates and quaternary ammonium silicates.
 39. Thecomposition of claim 23 wherein the water-soluble matal ion-freesilicate is tetramethylammonium silicate.
 40. The composition of claim23 containing from about 0.1% to about 3% by weight tetramethylammoniumhydroxide and from about 0.01% to about 1% by weight tetramethylammoniumsilicate based on the weight of the composition.
 41. The composition ofclaim 40 further containing from about 0.01% to about 1% by weight ofthe Composition of trans(1,2-cyclohexylenedinitrilo)tetraacetic acid.42. The composition of claim 34 wherein the titanium residue removalenhancing agent is hydroxylamine in an amount of from about 1% to about30% by weight and the nonionic ethoxylated acetylenic diol surfactant ispresent in an amount of from about 0.01% to about 1% by weight of thecomposition.
 43. The composition of claim 42 wherein the metal ion-freebase is tetramethylammonium hydroxide, the water-soluble metal ion-freesilicate is tetramethylammonium silicate.
 44. The composition of claim40 wherein the titanium residue removal enhancing agent is hydroxylaminein an amount of from about 1% to about 30% by weight of the compositionand the composition further contains a nonionic ethoxylated acetylenicdiot surfactant in an amount of from about 0.01% to about 1% by weightof the composition.
 45. The composition of claim 6 wherein thewater-soluble organic co-solvent is glycerol.
 46. The composition ofclaim 45 wherein the composition further comprises from a nonionicethoxylated acetylenic diol surfactant in an amount of from about 0.01%to about 1% by weight of the composition.
 47. The composition of claim19 wherein the composition further contains glycerol as a water-solubleorganic co-solvent in an amount of from about 0.1% to about 80% byweight of the composition.
 48. The composition of claim 47 wherein thecomposition further comprises from a nonionic ethoxylated acetylenicdiol surfactant in an amount of from about 0.01% to about 1% by weightof the composition.